Acting

Ramesh Sippy Academy of Cinema and Entertainment is one of the best in Mumbai. Great and supportive faculty. They also provide Mumbai University Degree. And also provide weekend short term courses in Photography too. Recommended.

Yes, you can join FTII in acting course. Please go through the prospectus of the course provided by the university to get exact information regarding the eligibility criteria.

Refer the link:
https://www.shiksha.com/college/ice-balaji-telefilms-institute-of-creative-excellence-andheri-east-mumbai-41500

You haven't mentioned any institutions. But generally, it is better to finish the class 12th before going for such programs.

Since you are from a business background, it would be difficult for you. But it's all about your influence and money. When applying for the visa you have show them proof that you are qualified to take the course. Getting an offer letter from the University is not a big task. But getting your visa accepted will be. You can apply for the Masters programme if you have significant experience in theatre field. Otherwise don't take the risk of losing money through visa rejection.