Engineering

First of all, I would like to inform you that Anna University is a private university so there is no limit of seats in any branch so you can search and take admission.

Hello Mohammad,
Almost every institution and states allow NRI's to seek admission in an engineering college. First you need to decide where you want to take admission. unfortunately rules and procedure is different at different college. However luckily everything is spelt out on webpage of concerned

I do not think that universities/colleges offers B.Tech in VFX and BFA.

Yes, you can but you should have and know the reason for your immigration. It can either study, work or family. Only on truthful basis that is with proof, you will get a visa.

You need to score more than 90%.

If you are placed in a company in UK or US then you will have to migrate.