Which is better according to placements in CSE: IIT Roorkee, IIT Guwahati or BITS Pilani?

I think there is no point of comparison. It is always IIT Roorkee > IIT Guwahati > BITS Pilani. But if you live in North India, it is quite possible that you wouldn’t like to go to IIT Guwahati. In that case IIT Rookee > BITS Pilani. There is not point of discussion comparing the oldest engineering institute of Asia ( that too the best IIT after the old 5 IITs) with BITS Pilani. Though BITS Pilani is a very good institute for CSE but in comparison to IIT Roorkee it is not comparable. If you are getting CSE at IIT Roorkee, there is no point of a second thought to it. It is better as a institute than BITS Pilani.