is there any cut off mark for oc

You are not clear about what do you mean by the category OC
the categories wise reservations exist in India in the different examinations are SC, ST and OBC a and OBC b
The cutoffs usually are lower for OBC a and OBC B students than the unreserved category students
SC cutoff slower than the OBC cut offs and ST cutoff for the lowest of all those available except for the paralyzed of PH candidates who have the lowest cut offs of all especially if they are combined with other reservations like SC and ST

Hey

oc as in what category are you talking about please be specific

there is a cut off for every category in NEET be it UR/OBC/ST/SC

good luck!