Hey

The final cutoff for JEE Mains would be declared after the second attempt of JEE Mains and accordingly it would be declared for eligibility of Advance. NTA would accumulate the normalized score and according to total number of students appeared, cutoff would be calculated.

But by last year the cutoff percentile to appear for JEE Advance for General category was 89.75 percentile, so you have good chances of qualifying JEE Advance also this year the expected cutoff percentile is around ~89-90 percentile that would be in your favor. For more details follow the link; JEE Mains 2020