Hiii

You can go for M.Tech Cosmology if you are very much interested in this field. 
I can provide you a list of colleges where you can apply for MTech in cosmology

• Raman Research Institute
• Inter University Cent for Astronomy and Astrophysics, Pune
• Osmania University
• Cochin University of Science and Technology
• Indian Institute of Astrophysics
  
  

For any more help feel free to ask.
Thanks!