Hello Satyam. Thanks for contacting Careers360 and we hope we will be able to answer your query. 

I am answering the question: "Are class 12 marks important for GATE?"

The answer to this question is: No. In fact there is no such criteria mentioned until now. For appearing in GATE they don't even ask for 10th and 12th score.

For details I would advice you to visit the official site for GATE:

• http://gate.iitg.ac.in

Hope this helps you and all the best!