Cut off for general is 89.75 percentile and for obc is 74.31 percentile ...If you are from obc category then you are qualified for jee advance  otherwise not.. 

Hello Soumya

Congrats For Your 77.76 percentile in JEE mains.

If we Consider total no of students to be 10 lakh

and apply the formula

Rank =( total no of students -( percentile*0.01*total no of students))

then your expected rank would be Rank = 222400

We Cant say the qualified Percentile for JEE Advance before NTA

I hope you get my point

Thank You and GOOD LUCK!!!