So you have paid the amount in JOSAA counselling. For that you can follow the information provided below to contact JOSAA:

For any query related to NITs,IIEST Shibpur, IIITs and Other-GFTIs admission, Please Contact

Chairman
CSAB-2020 & Director
MNNIT Allahabad
Prayagraj - 211004
Email: helpcsab2020@mnnit.ac.in
Phone: +91-532-2546144

For any query related to IITs admission, please contact

Organizing Chairman
JEE (Advanced) 2020
IIT Delhi, Hauz Khas
New Delhi - 110016
Phone: +91 11 26591785
E-mail: jeeadv@admin.iitd.ac.in (mailto:jeeadv@admin.iitd.ac.in)

I hope my answer helps. All the very best for your future endeavors!