Physics

You can take admissions in Dehradun, Uttarakhand. I would like to suggest you that you should go for the below colleges which are the best engineering colleges in Dehradun:
Graphic Era University
Tula's Institute (this is the best college according to me)
Dehradun Institute of Technology.

You need to have at least 50% marks for admission in M.Sc Physics.

Hi, DAV, Chandigarh does not have B.Sc. (H) in Physics. Like Lovely Professional University, DAV University has this option.

Those interested in becoming criminologists usually pursue a minimum of a master's degree in the field. You could start with a baccalaureate degree in criminology, psychology or sociology. Criminologists also need to understand laws and law enforcement procedures, so you may take criminal justice courses.

For masters, you need to apply for GRE but some colleges ask for TOEFL or IELTS score as well.

Purchase GRE book by ETS publisher. It covers all the relevant topics for GRE.

As per your marks, you have cleared the basic eligibility criteria for IIT.
But to get admission in IIT, you have to clear JEE-Advanced with a decent rank to get admission in your dream branch. So, all the best for future.