All the colleges and universities that you have mentioned are premier colleges of India known for their quality education. When choosing which is a better brand and reputation, I would go with BITS Pilani. While IIIT and Delhi University are decent options, BITS Pilani is way ahead of them.
The brand value of a college has two aspects, its national and international reputation. So, I will be covering both aspects to give you a proper insight into the brand name of NIT Delhi:
Nationally
Internationally
Ultimately, the brand name and reputation do not matter and it’s your efforts that count.