Hi,

Thapar releases the application form just after the JEE mains results are declared. And according to the notice published by the Institutes admission commitee, a student can fill up the application form anytime of the year. It is always their on the college website.

You may also take admission as a december entry, you would just have to give an easy exam on JEE mains pattern which is conducted in college premises itself. You will hae more chances of getting a good branch at that point of time. 

So yes you can either fill it now or In december according to your interest.

Thank you