Try to follow the same process you have gone through at the first place. If that process doesn't suffice you a second chance then you should write an official mail or a formal call with the organizing institution and get your problem discussed in details. In this way , you will get the correct information about the next necessary step.

Also do keep a visit to the official website of GATE and see if there is a suggestion or any details regarding the number of times you can rectify your notification.

This are the potential steps according to me. And I hope it will help you. Wish you a good luck so that your problem gets resolved as soon as possible.