NTA Scores are given in percentile.
Percentile is calculated by the ratio of the number of values to the total number of values . You cant say/depict your actual score/rank from your percentile neither can you calculate it by only marks. To calculate the actual score/rank/percentile you would need to know the number of students who appeared in the examination and the highest score, average cut offs and the highest score. while as marks are calculated based on the right questions you have attempted, out of the total marks you have obtained for the right number of questions marks from wrong questions marked are deducted from the total.

NTA announces the result of JEE Main/Advance in the form of a percentile score in every attempt or exam of JEE Main/Advance. The All India Rank (AIR) of candidates in JEE Main is calculated by taking the best score out of four attempts and are provided after the result of fourth exam. Candidates are able to check the detailed marks vs ranks of JEE Main/Advance after the conclusion of the exam.

Two types of ranks are given at the end:

1. AIR: All India Rank
2. CR: Category Rank

AIR is the overall rank obtained by the candidate respective of their category and CR is the rank candidates got in their respective category (General/EWS/SC/ST).

Hi Chitrankar,

If you get 87 marks in JEE main exam, you rank would be approximately in between 90,000 to 1,00,000.  Also, Above is the range of your possible rank. The predicted rank may vary due to JEE Main tie breaker rules for the same score. You will not get NIT s with this marks and rank. For NITs, You have to secured minimum of 30,000 rank. Your percentile would be nearly about 82-87.

If you have secured this rank you have a chance to get these colleges:

Walchand institute of technology

RAIT Mumbai

Pondicheery Engineering college

Vidyalankar institute of technology

Ujjain Engineering college

Amity University

PTU Punjab

MIT Academy Pune

UIET Punjab

These are few colleges, you will get on these marks. But you didn't get any NITs with this marks.