Harvard and similar schools aren’t harsh. They’re liberal arts institutions. At the undergraduate level, their focus is different than that of the individual who is merely a walking/talking calculator.
i'm a student with from india, what are my chances of getting into Harvard, princton, darthmouth etc
You don’t necessarily get to decide this.
In the case of Princeton for example, ANY full-time study post high-school disqualifies you from admission since they would consider you a transfer and they don’t take transfers.
Other schools might consider you a transfer applicant in any case regardless of your intentions to “apply as a freshman.”