Hello Vivek Kumar  ,

Thapar University, TIET Patiala, Thapar Institute of Engineering & Technology and TU Patiala.

The minimum marks required to get into Thapar University in is to have 20% marks in JEE Mains that is scoring minimum of 72 marks will make you eligible for admission.
But you will not getting any Core Branches.
Also if your marks are around 90 don't expect seat from direct counselling.
You will get seat during Final In-Person On the Spot Counseling. 

I am giving you the cutoff of ranks and marks that were published by Thapar University:

     Branch                           cutoff (outside punjab)                                     cutoff (punjab)                  

Chemical Engineering                            213608 (55)                                           261281 (49)

Civil Engineering                                    146795 (65)                                          300069 (45)

Computer Engineering                            32471 (125)                                          86452 (84)

Computer Science and Engineering          46770 (109)                                         223247 (53)

(At Derabassi Campus)

Electronics and Communication              57903 (100)                                           303136 (45)

Engineering

Electrical Engineering                             112167 (75)                                            280141 (46)

Mechanical Engineering                          78847 (87)                                              291238 (45)

So, to be at a safer position of getting admission, I would prefer you to score anything above 75 Percentile, if you are not from Punjab. Now if you are from punjab, score anything about 70 percentile would work .

All the Best!