Hello Dhanalakshmy! Humans tend to make mistakes but this one is not rectifiable. There is no possibility for you to change your category now. NTA provided a stipulated time until September 23, 2020 for the category correction. During the counselling, you will have to produce a proof for your OBC-NCL category, which you aren't. There are chances for your government admission to be cancelled. Kindly be careful while filling every details in any application form.