Hello Rohith

See you have got 86 percentile that means you are ahead of 86 percentage candidates or you are below 14 percentage candidates.

The exact percentage of people ahead of you is

100 - your total percentile

Formula to find out rank from percentile is

(100- your total percentile)  x total number of candidates appeared in 2019 / 100

Now 874469 candidates appeared in January 2019 Jee main  , so your rank is

(100-86) x 874469 /100

So your Jee main 2019 January rank is 12,2425.66