Once you are done with your B.Sc in physics then you can go for M.SC in Physics thenM.Sc +PH.D ( Physics and Astrophysics) and lastly P.hd course in Physics can be done.

Colleges for Nuclear Physics -
Centre for Nuclear Medicine, Panjab University
MIOT Academy of Allied Health Science
Manipal College of Allied Health Sciences
School of Chemical & Biotechnology, Sastra University
College of Engineering Studies, University of Petroleum and Energy Studies
Faculty of Engineering and Technology etc.

Colleges for Astrophysics -
JNTU College of Engineering, Hyderabad
Indian Institute of Astrophysics, Bangalore
Osmania University
Indian Institute of Science, Bangalore
Birla Institute of Technology & Sciences, Pilani
Punjab University
Institute of Fundamental Research, Tamil Nadu
Astrophysics, Tata Institute of Fundamental Research, Pune etc.

Good Luck!!!