M.Sc

To become a physics professor in IIT and any other TIER-1 colleges like IITs, 5NITs, DTU, BITS, and IIITH is not an easy task.
You need to have a PhD from country's most reputed college like like IISc Bangalore, IIT-Delhi, Bombay Kanpur. It's all about decorating your profile by doing some really good research papers. If you manage to prove your worth in your research area, and it impresses your Head of the Department; you can get a job as guest faculty. And you get paid for this. Actually, there's a high possibility of you getting chosen as an Asst. Prof of the same IIT from where you've applied for your Doctorate.
WHAT TO KEEP IN MIND:
1- You should be a pass-out from TIER1 colleges which were mentioned above.
2- Your profile is minutely checked, UG College, PG college and your CGPA should be &get;8
3- you need to impress the faculty and the H.O.D of the colleges where you want to teach even if you can't 'Teach' well, it doesn't matter unless you're highly qualified.