Quantos níveis o modelo Weretiger leva para ser concluído e por quê?

I think lycanthropy is better explained here on d20srd. The weretiger template class is based on this one. Template classes are ways for player characters to gain a multi-level template over time. But with few exceptions, completing a template is the same as having the template the class is based on.

The actual level increase for a natural weretiger is +9 (or +8 for an afflicted weretiger).

+3 of these levels (2 for afflicted) are a level adjustment.

Level adjustment: Same as the base creature +2 (afflicted) or +3 (natural).

The template is designed to account for this by putting all the differentiating attributes of a natural lycanthrope in the 3rd level, indicating that an afflicted lycanthrope should only take the first two levels. In effect the weretiger class is just a specifically worded instance of a more generic lycanthrope class.

The other 6 of these levels are the level-adjusted racial hit dice of the animal. In the case of a weretiger, the base animal is a tigre, which has 6 racial HD and no level adjustment. These racial levels are interpreted as class levels in the Tiger class.

In addition, a lycanthrope’s character level is increased by the number of racial Hit Dice the base animal has

So your character has 6 levels in "Animal". These levels give HP, Base attack Bonus, saves and skills as usual for the animal class

Features An animal has the following features (unless otherwise noted in a creature’s entry).

• 8-sided Hit Dice. Base attack bonus equal to ¾ total Hit Dice (as cleric).
• Good Fortitude and Reflex saves (certain animals have different good saves, for instance dire animals have good Fortitude, Reflex, and Will saves).
• Skill points equal to (2 + Int modifier, minimum 1) per Hit Die, with quadruple skill points for the first Hit Die.

6HD+0(Tiger)+0HD+2(afflicted Lycanthrope)[or +3(natural Lycanthrope)] = 8(afflicted) or 9(natural) levels

A weretiger takes at least 1 level in the template class homem-tigre to become a lycanthrope então may take levels in the class tiger (lycanthrope) to gain tiger abilities

I suspect the column "Lich and Weretiger Template Classes" is causing some of this confusion with this section:

Each lycanthrope template class has three levels, but only natural lycanthropes can take all the levels it offers. An afflicted lycanthrope can take only 1st and 2nd levels in the class, since his level adjustment is +2 instead of +3.

Lycanthrope template classes also follow special rules relating to the benefits such characters acquire from their animal natures. The template [class] allows for a level adjustment of +3 (or +2 for afflicted lycanthropes), but that value does not include the Hit Dice from the lycanthrope's animal form. So while a 1st-level human natural weretiger warrior (as presented in the Monster Manual) has a level adjustment of +3, his ECL is actually 7—1 from his warrior Hit Die, +3 from the template, +6 for his tiger Hit Dice.

Keep in mind that the example starting with his ECL is actually 7 is mistaken and may be the source of this entire argument! I mean, really, 1 + 3 + 6 = 10 not 7! That is, the creature's ECL is, in fact, realmente 10—that's 1 for that level of warrior, +6 for the animal Hit Dice, and +3 for the Level Adjustment given by the Monster Manual (178). In other columns, some lycanthrope template classes like the werebear e a lobisomem are correct, but in others template classes like the wereboar e a homem-rato include gross copy-and-paste errors that should go a long way toward proving that these columns do, in fact, suffer some editing issues rather than the weretiger template class possessing, like, some different kind of alternative stealth rules-as-written advancement. Anyway, the column continues below.

Thus, in addition to the levels offered via the appropriate lycanthrope template class, each kind of lycanthrope also has a separate (optional) class progression for his animal abilities. Essentially, a character progressing as a lycanthrope multiclasses into the template class and can also multiclass into the appropriate animal class if desired.

(Emphasis mine.) This means, for example, a human fighter 1 that takes all 3 levels of the template class weretiger does não also get 3 free bonus levels of the class tiger (lycanthrope)! It sounds like the argument's with someone who believes the template class weretiger overlaps with the class tiger (lycanthrope). That's not what the text says (although it's possible for the mistake in the example to lead a reader to that conclusion). The classes are taken in succession or interleaved but não concurrently. In short, it sounds like the argument that's being made is this:

DM: Explain this to me again.
Player: So I'ma gonna take 1 level in fighter then 3 levels in the template class weretiger that gets me 3 levels in the class tiger (lycanthrope). Then I'ma gonna take the remaining 3 levels of the class tiger (lycanthrope). Then I'ma gonna take all 6 levels of the class tiger (lycanthrope) again. Bang! A level 13 PC!
DM: What?
Player: Yeah, I'll have 13 Hit Dice, base attack bonus +9, and my character's Strength score will increase by +24! All at ECL 13. It'll be awesome.
DM: Um. Let me pose a question about this on RPG Stack Exchange, okay?

Despite possibly being misled by a bad example, the player não pode do what he describes above according to the rules. The player wants, essentially, 3 free levels e to take the same class duas vezes, and, while I truly do understand that desire, even being a weretiger doesn't allow aquele unless the DM for some reason makes an extremely generous exception. (Has the player recently bought pizza e booze?)

An example of how the template class actually works

In a low-powered game, Chris's PC, a commoner 1 named Sirc, is bitten by a natural weretiger. Miraculously, Sirhc survives. Unsurprisingly, Sirhc fails the saving throw against her weretiger attacker's supernatural ability curse of lycanthropy. Further, Chris decides its better for Sirhc to be afflicted with lycanthropy than be dead, so, rather than consuming belladonna by the bushel, Chris quietly accepts the fact Sirhc's next effective level is pretty much locked in.

When Sirhc has fallen into a few 10-ft. pits—and lived, thank you!—and committed copious amounts of toad murders, she's finally accumulated enough XP to advance to level 2. The DM mandates that because Sirhc's been afflicted with the curse of lycanthropy Sirhc must take the next level in the template class weretiger. From her level in this template class, Sirhc gains apenas the template class's specials; the template class provides no increase to Sirhc's base saving throws nor to her base attack bonus nor does Sirhc gain secretly the first level of the class tiger (lycanthrope).

After having taken 1 level in a standard class and that 1 level in the template class weretiger, for her next and successive levels, Sirch has three choices:

1. Take another level in the template class weretiger. (As an afflicted lycanthrope she can take only the first 2 levels of this class.)
2. Take a level in the animal class tiger.
3. Take a level in a standard class or prestige class for which she meets the entry requirements.

(Unlike racial classes, template classes needn't be finished before leaving them: "Characters are not required to complete all the levels of a given template class in uninterrupted succession," says Reynolds's Savage Progressions Web column "Obtendo uma campanha intermediária de modelo"—the column "Lich and Weretiger Template Classes" is part of this series.)

Observação: You can read more about the template weretiger in this 2005 PT Mundo fio.

The version of weretiger linked in the question is taken directly from Savage Progressions: Lich and Weretiger Template Classes, an official article detailing a method of taking the weretiger template one level at a time. If you're using this, ignore the standard Monster Manual lycanthrope rules.

This weretiger progression is, confusingly, divided into two separate classes: The Weretiger Template Classe The Tiger (Lycanthrope) Class.

O Weretiger Template Class grants no hit dice. Taking one level of this puts you in the same situation as a tiefling character, e.g. you may be a 4th level fighter for all intents and purposes, except for gaining experience, where you are considered a 5th level character.

If you have taken at least one level of the Weretiger Template Class, you now qualify to take levels in the Tiger (Lycanthrope) class. This faz grant hit dice as normal.

A character who takes all possible levels by ECL 11 (e.g. Fighter2/Weretiger3/Tiger6) will have 8 hit dice (two Fighter, six Tiger), but count as an 11th level character for the purposes of how much XP he needs to level up. Your six Tiger levels grant +4 base attack, but your three Weretiger levels grant no base attack, because they grant no hit dice.

(An additional quirk is that if you acquired lycanthropy rather than being born with it, you may not take the third level of Weretiger Template Class.)