Dear leaner,

If you submit your signature copy there is no need for thumb impression, but generally people who are illiterate, blind with other disable will express by placing thumb it's legal in any application so , if you are worried about that don't, here  you can call the college by 04712515502. They are many faculties numbers in college website contact them .

https://www.cet.ac.in/contact-us/ .

All the best.