Hello Dear,

First you should be very good in studies. Even if you have more than 90% you don't have any guarantee of getting into Harvard .

Also you should have many extracurricular activities in your resume (one is also enough if you have done it extensively).

Admission process in Harvard University follows certain process.

1. You have to appear for SAT and 2+ subject SAT (more the score more the chances).
2. Also you have to give TOEFL and have to score 100+ just to apply.
3. You must have 2+ recommendation letter from your teacher.
4. Get your mark-sheets evaluated from external agencies ( if required).
5. You also should have your midterm marks before applying(in case you are appearing)

These are the basic things that you have to follow before applying in Harvard.

Good Luck