I got 120 in jee advance and iam obc but I got in physics paper 1 is 6marks and paper 2 is 6 marks

Hello dear aspirant,
Hope you are well.

120 is a good score for an OBC candidate in JEE Advanced and as far as the sectional cutoff is considered,  for OBC,  the sectional cutoff remains at 10 to 12 marks. In 2018, the subject wise cutoff for OBC was 11 and in 2017 the subject wise cutoff for OBC was 10 marks. So don't worry,  as per the last year trends,  you will clear the sectional cutoff,  the rest depends on the this year cutoff because the pattern has changed,  so,  the cutoffs may also change.

Hope it works.