All the three campuses, are academically the same, the degree awarded to you at the end of your graduation will be the same regardless of your campus. Also the placements at Hyderabad and Goa are pretty much the same and are also only slightly behind pilani, i guess the difference in average package offered during placements in less than 2 lakh now.
The only difference in between the three campuses is the peer group. Students at pilani will have a higher bitsat score on average and peer group matters a lot in college. Also another thing is the infrastructure, since Hyderabad campus is new, the infrastructure there is top notch. I will be attaching a picture of their auditorium below.
As far as comparison with NIT is concerned, if fees is a major issue for you ( remember you can always take an education loan without collateral to pay your fees ), then go for NIT. But the campus life and peer group that you will get at BITS is worth paying for in my opinion.