Hello student you can fill the application form on the official website of TIET, refer to the link mentioned below it'll redirect you to the website.
Last date to apply is 31st July 2020.

https://admissions.thapar.edu/online-application-form.php?utm_campaign=TIET2020&utm_source=OML-Adwords-Btech&utm_keyword=thapar%20institute%20of%20engineering%20and%20technology&utm_medium=PunST18

Eligibility - Candidates must passed or appearing class 12 with physics chemistry and mathematics with minimum 70 percent marks aggregate from a recognized board (65 percent for sc/st)

Feel free to comment if you have any doubt
Good luck