BE course is theoretical  where as btech course is practical. There is no difference in both . As you mentioned that you are good at computer science . So choose btech computer science engineering branch .so  btech is better for your career in isro

Dear aspirant, first of all I would like to tell you that B.E and B.Tech both are the same. There's no difference regarding the scope and courses offered. Both of them have equal value.
Coming to your next question. If you are good in Computer Science then you can persue Computer Engineering and after graduation in CSE you can give ISRO CS exam to compete for the job at ISRO.
You can also choose Aeronautical Engineering offered by many universities in India. And if this degree comes from IIT then  it would be great help to you.
So, you can choose any of the two engineering courses and it totally depends on your interest.
My vote will be, you should go for CS as you are already good in that subject so you won't have to start from the beginning.
All the best :)
Hope this helps :)

Hello X Semantha,

If talk about carrier of engineer in IRSO,so there are more chances to get placed in this company if you scored a good rank in GATE exam.So with Computer science also there are more chances of getting this company with the good rank in GATE exam.So you have to work for getting a good rank in GATE exam and prepare for that.