Hi

Hope you are doing fine.

You can get into ISRO after ms astrophysics. The path will be hard but if you have that passion in you to get there its not that tough. Also a lot of candidates would be aspiring into get into ISRO, so there would be such as competition. As ISRO is a research oriented one, it would be good if you have a Ph. D in hand. ICRB will announce the vacancies . You can apply for the posts. Written examination is conducted and selection will be based on that. After that there would be a interview.

Wishing you all the very best.