My BITSAT score is 299. which brnch can i get.
At this score of yours you wont be getting into pilani with some core courses . Only you can get there at Pilani will be civil but you may get seats alloted to you with good branches at Goa or Hyderabad.
Refer to the last year cutof details : -
Among all of these Civil at Pilani will be the best option for you in terms of placement and future prospects.