He/she would remain in OBC quota. Your score will not decide your category. 

You should have your category certificate with you. That certificate is a proof to your category being an OBC candidate. 

Score good!!! 

Best of luck!! 

Dear Sir/Ma'm, whatever your category you have mentioned at the time of filling up the NEET form, that very category will be taken into consideration for the whole duration till the counseling wnd admission into any college of your choice. Hope this helps.