No,percentile or percentage is not same thing.Percentage means how many marks you get out of 100.But percentile means percentage of total candidate(in particular session) who score equal to or less than your raw marks.Raw marks means your score.Here percentile method is adopted as it is not easy to maintain the same level of jee mains paper for 6 session.Thats why percentile method is adopted so that no one get disadvantaged of tough paper.For every subject (phy,chem and maths)  percentile is adopted.

You can ask if you have any doubt.Feel free to ask.

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