Since you have declared an interest in being a physicist, I am assuming that you are in it for the long haul and plan to complete your PhD, postdoctoral studies, etc. I would suggest that you appear for entrance exams that will allow you entry into integrated MSc-PhD programmes. You could sit for the TIFR entrance exam. Also, you can give JEST. If you clear JEST, it will open up avenues to several premier institutes in the country as many of them accept JEST scores while considering applications. IUCAA has its own entrance exam INAT. However, as far as I am aware, it does not have a MSc programme (the entrance exam is for PhD aspirants). The registration dates for the entrance exams for the academic session 2016-2017 are already over so start studying with the goal of joining in the 2017-2018 academic session. This is my limited input that I can give to you (I am no expert in this topic) but I hope that it is of some help.