Well they have given quite a few ways to reach out to them. You should visit the contact us page on the JOSAA website.

For IIT related queries :- +91 1332 284272

email :- jeech@iitr.ac.in

For NIT/IIIT/GFTI rekated queries :- +91 431 2504333, +91 431 2504334, +91 9489979868

email :- csabhelpdesk@nitt.edu

If the contact numbers don't work then send them an email.

Be sure to ask any query during the given timings 

Timings :  09:00 AM to 08:00 PM (Monday to Saturday) , 10:00 AM to 06:00 PM (Sunday)