Hey,
First off,stop stressing yourself out. Then be sure of your calling. Ask yourself whether you actually want to study Masters of Science in Physics or it is just that your friends want to do the same
After you have got your answers,get into the preparation mode. See,there are entrances like IIT JAM by clearing which you will be able to study M.Sc in IIT colleges across India plus,you can also study in Indian Institute of Science,Bangalore. There are other universities as well which conduct their specific entrance tests like The University of Delhi,Banaras Hindu University,Jamia Milia Islamia. The syllabus is same for all.
Hope this helps you.
Good luck.

Dear student, you need to start preparing for the entrance exams conducted for MSc physics honours by various universities in your third year itself. Delhi University has its own entrance exam for admission to Masters courses. You can go for it and even you have options like Amity University, Banaras Hindu University and a lot more.