There is no facility to change/correction any details at any stage.
According to JIPMER MBBS 2016 Information Brochure
In case the candidate has found an error of entry committed by him/her in theapplication, a new application has to be submitted along with the prescribed. The earlier application will automatically stand cancelled.
No refund of fee paid earlier will be done.
I would suggest you to please contact JIPMER Helpdesk:
Helpline number - 18002660371
Email ID - firstname.lastname@example.org