I am a student at BITS Pilani. Both the campuses of BITS have their own advantages.
Here are a few parameters to compare the two colleges-
You should choose BITS Pilani as it offers cost-effective education, and the institution has strong ties in the Indian market. But you can opt for the BITS Dubai campus if international exposure is more important to you. Moreover, this campus provides career opportunities in Dubai, so if you wish to settle in the UAE, you can opt for this campus without hesitation.