Hello

JEE mains 2019 qualifying cutoff percentile  for different categories is given below

General :-89.7548849 percentile

GEN-EWS :- 78.2174869

Other Backward Classes (OBC-NCL) :-74.3166557

Scheduled Caste (SC) :- 54.0128155

Scheduled Tribe (ST):-44.3345172

PwD :- 0.11371730

But qualifying  cut off percentile keeps changing every year depending upon various factors like number of students that appeared in the exam, kind of marks obtained by them , toughness level of the examination etc.

Now , you have not mentioned the category you belong to so I am assuming you from general category and if you are from general category then you should try to get at least 90 percentile in your JEE mains 2020 to qualify it and to be eligible for JEE advanced

Thank you