I would like to inform you that as the April attempt is yet to convene , the percentile vs marks trend is yet to be prepared .To give you arough idea marks around 18-190 can fetch you 99 percentile and something around 170-180 can fetch you 98 percentile. Again, it differs from shift to shift. For time being you can go through the following link to go through the percentile vs marks of JEE Main 2019:
Wishing you all the best for your April attempt.
Percentile is the criteria which is introduced by NTA for normalization of JEE Scores 2020.
Some conversions are:-
17 to 1 marks - 31 to 9 percentile
27 to 18 marks - 49 to 33 percentile
37 to 28 marks - 62 to 49 percentile
47 to 38 marks - 74 to 64 percentile
57 to 48 marks - 81 to 75 percentile
67 to 58 marks - 87 to 82 percentile
77 to 68 marks - 90 to 87 percentile
87 to 78 marks - 92 to 90 percentile
107 to 88 marks - 95 to 92 percentile
107+ marks - 95+ percentile
You may refer to the source article for more detailed information
If you are interested in knowing colleges for which you are eligible then you should go to the link mentioned below.
Link - JEE Main College Predictor
Hope it helps you.
NTA has announced the normalization of marks with the percentage .Ranks is derived on the basis of percentage. It is done by NTA for making it easy since JEE mains is conducted multiple times.
Using this article you can understand the percentage vs marks using the previous trends
Hope this will help you.