Hello Deepak...

Yes, obviously you can join ISRO after MSc in Space Science. Also, you can pursue following advances. 

1) First completion your BSc and MSc with first division/65% marks/6.5 CGPA on a scale of 10. 

2) There exists ISRO Centralized Recruitment Board (ICRB) which leads a placement test. 

3) Sign on to ISRO's site and search for Vacancies/Recruitment alternative and check for any situation of intrigue. 

4) Register for the test. 

5) Look at the example of earlier year papers and plan well. 

6) When chosen, you will get a require a meeting. 

7) Clear the interview. 

8) Join ISRO.

Hope these will be helpful..

All the best!!

hello aspirant,

most of the vacancy comes under isro is like scientist-b post. they take btech engineers for that.. but as isro is a indian space research institution and it has demands for masters of space science candidates. however vacancies are different in every times. there are many internship programmes offers to students of space science in isro. you may join there. so please study well and hope for the best.