Hi dear,

Hope you are doing well!

Now let's go through your question.

As you will be knowing that percentile indicates how many students have been outperformed by you in exam.

The Top 20 percentile means that you are ahead of 80% of the people who have given the exam.

NOTE:

Percentile = no. of student have marks lesser than you / total no. of students appeared in the exam X 100

Your percentile should be >= 80 or you should have have your board percentage greater than or equal to 75%.

Hope it helps!

Thank You & All the best!