Hi,

To become professor, more than any university, what matters is your skills and knowledge. To become a professor in top IITs or any other institutes, you require a PhD. Apart from that, you can join any government college / university to acquire that degree. Whatever, course you choose to study, it is must to have knowledge in the said subject as apart from educational qualification, an Interview is also conducted by the top IITs which tests your knowledge and skills . So, focus more on that area and acquire degree from any of your interested college/university.

You should have a original and a well furnished research paper. University doesn't matter but the work and research you have done matters. If you have a phD from a foreign university with a poor research won't make you avail a professorship in IIT. You will have to be focused in your research , must have done a couple of postdocs which will help you to build a strong CV for IIT and then just apply for it. If you have a good research (I am not talking about subject but the material in the research must be original enough) then it will make your way easier to be a Assistant professor at Old IIT's.

Have a great day!