Hey,

After completing MSc  Physics at IIT,there are many job opportunities,the best companies come there for placements and the salary offered is also great. If you want to change your field you can even do that, for example you have interest in coding then you can even sit for placements for companies like Amazon that accepts students with strong coding background.

You can even assist a PhD professor,you can pursue PhD and if you are interested you can even work for Research and Development department. It's upto you,which one is the best for you that you have to decide.