Hi Lakshma,

If there is any detail that is wrong you can call the number given on CAT website or mail to the concerned authorities regarding this issue and get it corrected. If they do not correct it you can ask them to send across a mail stating that this was a mistake and you can use it as a proof.

There is no need to panic. It is maneagable by following up with the concerned people.

These are the contact details as given on official CAT website:

Call the toll free number 1-800-209-0830 (Toll Free) immediately and mail to cathelpdesk@iimcat.ac.in as the exam is tomorrow only.

Hey Lakshma,

I think there is no need to panic. According to me you should contact CAT exam department via e-mail or telephone and bring this issue to their notice as fast as you can so that before releasing the admit card your DOB could be corrected. 

All the best for your exams.

Thank you.