The mentors and research facilities at IITs are much better than at BITS Pilani. However, the passing process is as much more difficult at IITs.
BITS Pilani, on the other hand, is flexible to incorporate the changing scenario and a PhD from BITS Pilani is much more industry relevant.
One of my cousins had a bad experience at BITS Pilani during his Ph.D. in the Mechanical branch. According to him, a large number of Ph.D. students in BITS Pilani drop out because of the intense pressure for producing results. PhD students are burdened with numerous tasks including the evaluation work for B.Tech. The saving grace for Ph.D. at BITS is that under a guide, your Ph.D. will be completed in 3 years like an MS from IIT.
Considering my cousin’s experience, you should consult the alumni at BITS Pilani before choosing the institution for pursuing your Ph.D. Otherwise, BITS Pilani is a reputable institution and its Ph.D. degree will hold great relevance. More so, if you get the right mentors and the right facilities, the name tag of an institution becomes secondary.
Some of my seniors studied at BITS Pilani and while they may not know much about the IITs, they do know that the funds the institute is receiving are helping it grow more and more. The campus is being renovated and more equipment is being bought for the labs.
For study projects, lab projects, thesis, and the students who work under the faculty will be interacting with the undergraduate students. The interactions can be instrumental in honing your academics and other skills for success.
Some other standout features are:
Hyderabad also has a number of popular institutes and is a great place for students who are currently and willing to pursue Ph.D. As BITS Pilani is still growing consistently, the fees are getting higher. The money is poured into the expansion of the institute.