go to the link given below https://sche.ap.gov.in/ECET/PDF/APECET2021_NCC_MERIT_LIST.pdf

and see your  qualified ncc certificate and merit order priority number alloted to it.that number in merit number

hai Ajay,i was also from ap,Basically the special reservation was for some more reservation in seat allocation that is for NCC students if had NCC certificate in your shooling or in +2 in that certificate there will be the merit number given to you based on your NCC standared ,i mean like 'c' 'b'... like that according to your rank it will be in your certificate .Giving that merit number was the proof for them they can check your certificate directly in there records