Hi Manik.

The selection in Punjabi University is made on the basis of 12th board percentage and merit in JEE Mains. JEE Mains ranking of under 2.9 lakhs can get you a seat in Punjabi University's Computer Science branch. This cutoff is for general category. For reserved categories like SC/ST, the cutoff rank can go as high as 7 lakhs. I'd suggest you prepare well for the Mains in April and get a better college.

All the best.