Hi, UPESEAT eligibility criteria states:

• Candidates must have secured a minimum of 60% marks at Higher & Senior Secondary level (10th& 12th).
• They also must have secured minimum 60% aggregate marks in Physics, Chemistry & Mathematics at Senior Secondary level (12th).

If you do not want to give exam then you can be selected on merit basis.

• Applicants must have secured a minimum of 80% marks at Higher & Senior Secondary level (10th & 12th).
• They are also required to secure minimum 80% aggregate marks in Physics, Chemistry & Mathematics at Senior Secondary level (12th class).

It also takes through JEE MAINS.

Also you can go through the complete paper pattern here:
UPESEAT Paper Pattern

Good Luck.