Hey,

There is no undergraduate level course in India which gives you opportunity to specialized in Astronomy and Astrophysics. So in Undergraduate level, you should choose any course which can give you depth background of core Physics and Mathematics.

In IISER Pune, you can take two coures, Astronomy and Astrophysics and General Relativity and Cosmology in your 3rd and 4th Year. In Practical, you don’t need many Professors to teach you just these two courses.

All the best!!!!