What is cut off and persentile in JEE main.

Percentile scores indicates the percentage of candidates that have scored equal to or below that particular percentile in that examination and this is generally from a scale of 100 to 0 for each session of examinees. Your percentile score is the percentage of people ahead of you.
The cutoff of Jee Main consist of the minimum marks that have to be scored to qualify for Jee advanced. The admission cutoff of JEE Main will be the minimum ranks that have to be secured to have higher chances of admission into the participating institutes. The admission cutoff will be released by JoSAA authorities after every round of allotment, while the Qualifying cutoff is released by NTA.