Hi there!

As a matter of reality, there are very few colleges which have astrobiology program around the world. Talking about India, there is IARC (Indian Astrobiology Research Center) in Mumbai which has a three month distance learning progam which is probably a good start before going abroad. You can find courses on the same at the online platform like Coursera and pay some amount to get a verified certificate.

Firstly, take an undergraduate course in any of the following fields as your choice:- Physics, Biology, Chemistry, Planetary Sciences, Microbiology, Oceanology, Astronomy, Astrophysics, Biochemistry.

These all find their place in Astrobiology. After doing that I will suggest you to do Masters in the same field and enroll your name for Phd programmes in abroad universities.

Also please remember this always Astrobiology is not a field but a wide range of fields working in harmony for a specific goal. So you need to contribute your work by working by 1 of the courses I have mentioned about. Thank you.