India

Hello Hema,
Admission in Anna University is based on board's marks only so you have strong chances to get any good branches there.

With 96 marks in JEE Mains and having OBC category, it's quite difficult to get into any NIT/IIIT.
However you reside in Maharashtra, so there are fair chances that you will get admission in the govt. /private colleges of Maharashtra. So keep visiting your nearby colleges and gather information.

You may refer to the following link for top engineering colleges in Andhra Pradesh:
https://www.shiksha.com/b-tech/ranking/top-engineering-colleges-in-andhra-pradesh/44-2-100-0-0

NCR-Delhi is the best among both the campuses of SRM.

For biotechnology colleges in Andhra Pradesh, follow this link:
https://www.shiksha.com/b-tech/colleges/b-tech-in-biotechnology-engineering-colleges-andhra-pradesh

Hello Aryan,
There are several institutes in India which offer you to pursue a career in astronomy or space research. Below is the list of institutes.
IIAE Uttarakhand
MIT Madras
IIT Mumbai
Indian Institute of Astrophysics, (Bangalore)
Indian Institute of Science, (Bangalore)
Raman Research Institute, (Bangalore)
Inter-University Centre for Astronomy and Astrophysics, (Pune)
National Centre for Radio Astronomy, etc.

Tamil Nadu state board will conduct B.Tech agriculture entrance exam. So crash this exam and go on with your studies or try this course in private universities.

NID is the best institute for the course but you need to clear the entrance exam for the same.