I've got a rank of 4333 of iit-jee and a marks of 356 in Bits Pilani. My preferences are Computer Science and Electronics so please guide me.

If you get Pilani ofcourse go with it otherwise I would stronlgy advice you to go with NIT W or NIT A CSE because these two have done exceptionally well with around 8 lpa average pakage in recent years.

U will not able to get CSE or ECE at old IIT, so best option for u to go for BITS, Pillani. BITS is far better than new IITs

You will not be getting a good branch at old IITs. So wait and see if you can get CS at PILANI CAMPUS (Others not that good).

If not then look for top NITs like Kavish said.