I am getting a 3942 rank in the JEE Advance and according to my BITS score(383), I would get a CS or an EEE (electrical and electronics engineering) in the BITS Pilani campus. What should I choose in such case: IIT or BITS?

If you are keen on CS or EEE Branch then choosing BITS is a more sensible option.

There are only 5 IITs which are better than BITS and they are:

1. BOMBAY
2. DELHI
3. MADRAS
4. KANPUR
5. KHARAGPUR

With a JEE ADVANCED Rank of 3942, you will not get CS or EEE in the above 5 IITs so the next best option is obviously BITS PILANI.

If you are very keen on only CS Branch and do not get it in BITS PILANI, Pilani Campus then you might want to consider BITS PILANI, Goa Campus or BITS PILANI, Hyderabad Campus.

If you are fine with EEE Branch then you will definitely get it in the Pilani Campus itself.