Hello Sonali,
Thank you for your Advice .
I have Contacted multiple times over Email and Call But No reply for my email and They are not lifting my Call for 6 months. I have below details but no response from them. Could you please provide me any other Contact Details.

Central Seat Allocation Board – 2019
National Institute of Technology
Tiruchirappalli – 620 015
Tamil Nadu, India
Contact No. : +91 431 2504333, +91 431 2504334
E-mail : csabhelpdesk[at]nitt[dot]edu
Timings : 09:00 AM to 08:00 PM (Monday to Saturday) , 10:00 AM to 06:00 PM (Sunday)