Haha. Very funny question indeed.
To get into ISRO is not a joke. Many scientists working there are actually geniuses in their own field. Once try to know about a institute called IIST from where ISRO takes students directly as scientists(You are inducted into ISRO after completing graduation with some conditions). Many people will be actually dreaming about becoming a space scientist. Also many research scholars from highly prestigious institutions like IISC,TIFR which are well known around the world will also be there in ISRO. If you only have a undergraduate degree you can't get that far in ISRO.
Without Knowledge, Skill cannot be focused. Without Skill, Knowledge may not be applied., In your question you are just underestimating many other colleges in India.
There are some institutions in India specialized for some specific courses like Mathematics, Astronomy, Electronics etc.,
There are more than 30 premier research organizations working under the purview of CSIR.
Also there are these:
1. Indian Institute of Science (Bangalore)
2. National Physical Laboratory (New Delhi)
3. Defence Research Development Organisation (New Delhi)
4. Institute of Physics (Bhubhaneswar)
5. Tata Institute of Fundamental Research (Mumbai)
6. Inter-University Centre for Astronomy and Astrophysics (Pune)
7. National Centre for Radio Astrophysics (Pune)
8. Inter-University Consortium for DAE Facilities (Indore) Jawaharlal Nehru Centre for Advanced Scientific Research (Bangalore)
9. Institute of Mathematical Sciences (Chennai)
10. Centre for Advanced Technology (Indore)
11. Indian Spare Research Organisation- (1) Physical Research Laboratory (Ahmedabad); and (2) Space Physics Laboratory (Thiruvananthapuram)
12. Mehta Research Institute of Mathematics and Mathematical Physics (Allahabad)
13. Bhabha Atomic Research Centre (Mumbai)
14. Physical Research Laboratory (Ahmedabad)
15. Saha Institute of Nuclear Physics (Kolkata) S N Bose National Centre for Basic Sciences (Kolkata)
16. Raman Research Institute (Bangalore)
17. Indira Gandhi Centre for Atomic Research (Kalpakkam, Tamil Nadu)
18. Atomic Minerals Directorate for Exploration and Research (Hyderabad).
19. Indian Institute of Astrophysics (Bangalore)
20. Institute of Plasma Research (Gandhinagar)
What about the above institutions? Not knowing them doesn't make them unpopular. They are popular for those people working in that field. Apart from above institutions many top IITs also conduct research.
If you are thinking that IITs,NITs are the only popular institutes in India then you are completely wrong. Also the induction process in ISRO is too tough. People whom you see on the tv representing ISRO are actually geniuses in their own field. They do research in some fields which we actually can't dream about.
After doing some research about some well known persons in ISRO you can find that they had done their post graduation from some excellent institutions.
It's all about that research thing and the dedication you have to do a scientific work for a country. Yes many of the ISRO's staff are from non popular engineering colleges. Working in ISRO doesn't require a degree from popular institution. If you have the zeal to do research or work in an organisation like ISRO your almamatter won't matter. Only your knowledge and dedication matter. There is no way that because of some mediocre people working in ISRO it is able to compete with other organisations like NASA,ESA etc.,
Once try to know the specializations in space research field. You will almost have to possess godly knowledge in that field to become a good scientist. I am talking about people who design and make decisions in ISRO.
If you think that most of them graduated from a non popular college then you are completely false. Follow the links below.
Remember that research is not a joke.
A.S.KIRAN KUMAR
A. S. Kiran Kumar – Wikipedia
K.RADHAKRISHNAN
K. Radhakrishnan – Wikipedia
SATISH DHAWAN
Satish Dhawan – Wikipedia
Good that someone wants to know about this. Many people should be made aware of these things in India. Research should be of the utmost importance in any field.
If not popular make them popular dude, it's good for everyone.
Hoping that ISRO will be successful in it's future endeavours.
Jai hind.