Hello aspirant,

the eligibility criteria clearly states that the candidate has to just clear JEE main paper 2 that is b.arch paper to go for further studies in NIT'S. 

To study B.arch in IIT'S candidate has to give JEE advance and after clearing that candidate has to appear for  AAT ( architecture aptitude test ) 

candidate can appear for AAT only if he/she gets through JEE advance and score a rank there.

hope this information helps.

all the best ....!!!