Hello Bidisha,

Most if not all colleges offering masters in physics fill their seats based on merits. The top colleges offering MSc physics are given below

Delhi University

SRM University, Chennai

Indian Institute of science, education and research (IISER), Kolkata

Indian Institute of technology, Delhi (IIT D)

Viswa Bharati university

Indian Institute of science, education and research (IISER), Pune

You can find further information on the course and colleges in the link provided below

https://university.careers360.com/colleges/list-of-msc-in-physics-universities-in-india

Hope this helps and Good luck