Hi! In order to work at ISRO, candidates must have qualified B.E/B.Tech or equivalent qualifying degree in first class with an aggregate minimum of 65% marks or CGPA of 6.84 on a scale of 10. ISRO is a bit strict about the CGPA or marks, so ensure that you study well.

Sometimes ISRO recruits Scientific assistant/officer, basically BSc candidates. But the eligibility for Scientist - ‘SC’ is MSc in general stream. So you can join ISRO after your Msc as Scientist/Engineer SC and after Bsc as scientific assistant/officer upon vacancy.

I have enclosed the following link which contains all  additional details you need to know for ISRO recruitment.

https://engineering.careers360.com/articles/isro-recruitment

Hope this helps!