Hello Arpit Pathak

If you can write the exam on your own and don't need a scribe for JEE Advanced, then contact the helpdesk. Write a mail to the helpdesk or the chairman or a letter addressed to the chairman of the respective zonal coordinating IIT. Keep in mind that you will have to adhere to the formate of the request letter, so do be aware of the necessary guidelines for the same.

Hope it helps you.