For UG law, the selection is based on PU CET BALLB entrance exam. 

The name of the candidate shall be included in a Preliminary Merit List on the basis of attainment of a minimum of 15% (cut off) marks (10% Cut Off marks in case of a candidate belonging to Scheduled Caste/Scheduled Tribe/Backward Class) in the Entrance Test. The paper is out of 100 marks. So 15 marks for Open Category and 10 marks for SC/ST.

There is no other cut off calculation given but for merit, the calculation is that 50% weightage is given to PU BA LLB Entrance Marks and 50% weightage is given to Class 12 marks.

You can download PU BALLB sample paper from here.

Good Luck.