Hello Aspirant,

There are few universities in Tamil Nadu where you can pursue Bsc in astrophysics, the list us as follows-

• University of Chennai
• Institute of Fundamental Research,  Tamil Nadu

I will list some more universities for Astrophysics which are outside Tamil Nadu-

• Osmania University
• Indian Institute of Science,  Bangalore
• Indian Institute of Astrophysics, Bangalore

I hope it helps

Thank you