Hello aspirant,

The counselling procedure is online and for document verification you have to get your documents verified at the help centres. After the conclusion of JoSAA 2019 seat allotment, there will be a special round of counselling for NITs, IIITs and GFTIs. The allotment will be open only for those candidates who have successfully completed their JEE Main examination and secured valid scores so you have to verify EWS document at the time of counselling. And you have to submit your documents at admission. 

Hope you get clarified.

Best of luck!!