Seria o seu país de residência. Um visto F1 não estabelece residência. Um F1 é apenas para estrangeiros não residentes. Mais especificamente, sua nacionalidade no seu passaporte é o que você deve usar.
De acordo com tsua visão geral do visto F1
Qual é o objetivo do visto F1?
The intent of an F1 visa is to
allow an alien - a person who is not a US citizen or US national - to
study in the United States. The F1 visa is not intended as a work
visa. The F1 visa does permit some very specific kinds of work while
you are studying in the United States and immediately thereafter.
The reason for these work limitations is that F1 Visas are “single
intent” visas, which means that the United States government created
the F1 visa program so that aliens (non-US persons) can pursue an
education in the United States and return to their home country after
the education. The intent of the F1 visa is not to pursue work in the
United States.
De acordo com a esta pergunta de aconselhamento jurídico em relação ao país de residência, você pode colocar um dos dois países, mas a resposta correta é que você é residente do seu país de origem, pois é apenas um estudante nos EUA com privilégios mínimos.
You are correct, that is a confusing question, especially in your
current situation. Your country of residence is usually your country
of nationality or domicile, outside the USA, but in this instance you
can go ahead and type in "USA" if you so wish. Nothing bad will happen
as a result. Your TPS application will not be denied or RFE'd as a
result; don't worry.. Either way will be OK...
De acordo com esta site do estudante internacional
F1 Visa Qualifications In order to qualify, applicants need to satisfy and prove several strict criteria during an F1 visa interview,
including the following:
Foreign Residence F-1 applicants must have a foreign residence and
must intend to return there upon the completion of their studies.
Sponsoring Institution While on your F-1 visa, you may only study at
the academic institution through which the visa was granted. Financial
Support Applicants must demonstrate sufficient financial support — the
Study USA Financing Guide can help you prepare for this aspect of your
time abroad. Ties to Home Country All applicants must demonstrate that
they have strong ties to their home country. Strong ties consist of,
but are not limited to, the following: A job offer letter upon
completion of studies Assets (i.e., house, land, vehicle, etc.) Bank
accounts Family
Entrei em contato com o CBP para esclarecer isso e atualizarei minha resposta quando receber a resposta.