my marks according to the official answer key by nta is 126 out of 300 but my percentile 92.23 shown in results of jee mains session 2 . what can I do now ?

See it is a clear case of rank inflation. When students appear for the first session of the Joint Entrance Examination, Main, most of them are inexperienced and this translates at a higher percentile even for the lower rank. But, when the second session happens, the students know the process and as a result many of them score much higher, due to which even at high marks like 126 you get lower percentile as in your case.

You can check out some good colleges under your category and try to take admission in them if you don't plan to take a drop.

You can also use our college predictor to see your chances in all the colleges:
https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer

Hope I have answered your question. All the best!