I’ll tell you what I tell high school students from the USA:
“Being accepted to X University” isn’t much of a life’s goal.
A real goal is “I want to be a Physicist”, “I want to be a scholar of History”, I want to be a Civil Engineer", or “I want to work in health”. Alternatively it can be “I love many things and want to explore multiple directions”.
College is a means to reach a goal, not a goal, and focusing primarily on that means is really not useful. It is as though you need to get to the airport to catch a plane, but you are focusing exclusively on whether the taxi that takes you there is luxurious or is the latest model car, and not caring whether it will get you to the airport on time, or even to the correct airport.
Rather than planning your trip and packing, you’re spending your time finding ways to catch the “the best taxi”.
This, unfortunately, is not a plan. It’s an aspiration. It’s a hope. You plan to apply to “an IB school like Jaishree Periwal International School” and you hope that you will be accepted, you plan to study “two languages from Delhi school of foreign languages” and you hope that you will successfully learn these languages, and you plan to take the SAT, and you hope to score 1550.
You have no idea whether you will be accepted to any IB school, you have no idea whether you we learn two languages successfully, and you have no idea how well you’ll do on your SATs.
Which brings me back to the first part of my post: will attending an IB school and learning two languages help you in your plans for after college? If you are not successful at being admitted to Stanford (which is the most likely scenario) will these actions help you in being admitted to one of the many excellent universities that are in India? Alternatively, will they help you be accepted to, and then do well at, one of the many excellent international universities that are not in the USA?
Spending two years engaging full time in activities that are aimed solely at increasing your chances at admission to Stanford is a waste of your time, which would be better spent on activities which will help you succeed while at college and after you graduate.