Choose what interests you. If you are interested in Chemical Engineering, BITS Pilani is a great option. It offers decent academics and exposure. Core Chemical companies and oil companies recruit from the institute. Schlumberger, ONGC, Reliance, etc. are among the major recruiters for the branch. BITS Pilani placement highlights show the average CTC to be around INR 12 LPA for Chemical Engineering. 

But if you are interested in Mechanical Engineering, you should choose PEC Chandigarh.