Dear Ritika, For example, if you are studying in a class of 100, top 20 percentile means you should secure better marks than 80 students. In simple terms, your class rank should be between 1-20. Do not confuse percentage with percentile. Percentage is your score out of 100. For example if you scored 80 out of 100, your percentage is 80%. Your percentile shows the percentage of Candidates who scored lesser than you.