A menos que você seja um residente permanente, você precisa se inscrever da Índia.
Extraído do VFS Global Website (para a Alemanha, mas as regras são as mesmas em toda a zona Schengen):
Eligibility
Applicant must at least meet the following criteria in order to be eligible to submit a Schengen visa application:
- holding a valid passport/travel document
- holding a valid UK residence permit. In case applicant holds a short stay visa, a C type visa (see example here), for the UK, then applicant needs to apply for a Schengen visa from his/her residence country.
- applying for a short stay visa (Tourist: including Minors, Visitor Family/Friends, Business, EEA/EU and Swiss national family member or Airport Transit)
Finalmente encontrei a página no BLS (os agentes que lidam com vistos espanhóis no Reino Unido), que estabelece os requisitos :
UK residence permit. You must be a resident in UK to be eligible to apply. Your residence permit must be valid for at least another 90 days beyond your return date from Schengen area. Please provide original and a copy (If card type, please copy both sides)
Na Índia, você precisará fornecer seus detalhes da conta HDFC.