Firstly, Bitspilani does not offer robotics as main engineering stream.If you are interested in robotics you can participate in events and workshops based on robotics taking any other engineering stream. There are two technical teams in BITS called team robocon and team acyut. These participate in international robotics competitions.Kindly go through bits pilani website to gwt well informed with what are all the courses they offer.Also they have robotics based courses that can be taken as subjects. 

http://www.bits-pilani.ac.in