Hello Anshu, there's a solution if you have entered something by mistake. You can correct your mistakes during the form correction period which will take place during the third week of may in 2020. You can make the correction only through online mode. For changing your category, you would need a Certificate issued by competent authority. If you are asking about this year, then you can't do anything because the counselling is schedules next month, so it might be too late.

HeY Anshu,

Hope You are doing Well!

Well Dear,the correction date for the application form has been closed and the filled up information has been printed on the rank card,and correcting the rank card will be a bit difficult,you should contact the concerned authorities,they might help you.

Hope This was helpful!
All The Bes!

Keep Smiling :)