Hello,

The one time correction is offered but the date is long gone expired. the last date for correction was 28th march. The candidates can change their form duly.

Now its JUNE n i don't think there is any chance to change it now. 

please refer the link for more details it may help you:- https://upseeadmissions.blogspot.com/

You can take help of your college or go to University head office directly either Lucknow or Noida  and ask them to change it. They will ask for the documents to prove your caste but will make the changes or tell you the way to do it else you can email the entrance board regarding the same.

Hope It helps!