Physics Spl

Hi,
Your overall profile excluding your GPA seems quite good. Very strong LORs from your professors and a very strong SOP will be very crucial in your selection process. Universities evaluate a candidate's profile holistically and there is no single factor.Show your uniqueness and stress on why you should be considered. Do well.

You must target for IIT-JEE, IITs are best known institutes if you want to work in research field in physics-optics. After B.Tech you can go for MS-PhD from good US university to further carry your research work.
You must target IIT-JEE to get into top engineering colleges like NITs, BITs, VIT apart from IITs.

That entirely depends upon your stream.

You can go for engineering or you can go for Bachelors in maths. After that, you can go for Masters in field of maths. If you are going for engineering, than after graduation you can go for MS in research oriented fields from US university.

You must finish your 12th in Science stream.

If you want to pursue research and academics career then B.Sc (Honors) in physics is very good career option in comparison to run of mill Engineering degree from tier 3 engineering college without any good academic environment and placement records.