my rank if my percentile is 87.889 and my roll no is 210310001252
Assuming you are referring to JEE Main, with a Percentile of 87.889, you may secure a Rank anywhere between 130-135k. For more information and Rank Prediction do follow the link below
https://engineering.careers360.com/jee-main-college-predictor?icn=QnA&ici=qna_answer
I would advise you to work seriously, and improve your percentile with each subsequent session of JEE Main, for better prospects.