Hello aspirant

Percentile scores is used by NTA students. You must be knowing your 2019 Jee main percentile. So it's easy to calculate all India rank 2019 with help of this percentile. The formula to calculate the rank is

(100 - your percentile) × 874469 ÷ 100

Where 874469 is number of candidates appeared in JEE mains  January 2019. If you have appeared in April Jee main 2019 then use the figure 1400,000 instead of 874469 as in April session of jee main, 14 lakh candidates appeared .