Phone them. Go to the website, find a contact number, pick up the phone, and make the call. Say, I go to this and this school, study this and this curriculum, know this and this in mathematics, science, etc. Am I eligible for credits? For example, I would expect that coming out of CBSE, you already know differential and integral calculus. Believe it or not, many American students entering the same college will not already know those topics. Also, you can ask if there is any placement test you can take to skip some courses. Some colleges have those.