Is there any variation in the mains percentile and rank based on the session and date

Hello Greetings
From this your onwards National testing agency is organising JEE main in different shifts therefore to avoid any kind of partiality because the questions in each shift will be different and their main because that one paper is more difficult compared to other therefore to our any kind of this affects the national testing agency will create your absolute into percentile score with respect to the students appeared in your shift and percentile will be calculated upto 7 decimal point to avoid any bunching effect. So it may happen that someone with 340 score get better rank than someone who scores 345 if the paper of first candidate is more difficult. Therefore there is not any kind of partiality.
Hope this helps all the best.

Yes, there is different. From this year onward NTA is going to calculate percentile score for each day and each session so that there is part laity.