CBSE 12th

First of all, decide the sector of your interest. Whether it is in science, commerce, arts or some other fields based on your talents. Accordingly, choose your graduation degree or Diploma.

Hi Yaash, You have to do a lot of things to improve your profile and make yourself fit for Harvard. Exceptional academic grades, outstanding extracurricular activities and all-round profile are a must. You need to ask yourself why a top ranked university like Harvard should admit you and not why another strong applicant, you can then discover your potential and showcase them. Please visit the Harvard website, check the kind of students they admit and prepare accordingly. You will also find the fee structure on the website.

Which subject interests you most?
Make your career in the same field.

You need to qualify SAT exam.

Hello Rutuja,
Yes, you can apply for the program.

Depends on your bent of mind.
If you are a social extrovert person, go for business study otherwise engineering stream is rewarding.
Secondly, the place from where you do this course is important. Reputed colleges will give you a good start, irrespective of the course. So just see what is your academic performance and potential and decide accordingly.