SAT

You would be getting the report cards from your school. Just make sure the university you are applying might ask for a character certificate and an affidavit from your school, so make sure you get it as well.

If you want to study in 2018 then you have to apply for the university in October and November. For it, you have to take SAT in October, November or earlier.

You should focus on reading and writing because the language is complicated.

At the time of registration, it will ask you that which subject have you studied? What is your GPA?

Hi Aparna,
The eligibility is same as for DASA students. SAT is a requirement. You can check these on the official websites. I found this link for you, please check it along with your parents and try to understand what you have to do:
https://www.youtube.com/watch?v=JIaStdeFkVY

American Universities don't see only SAT and TOEFL scores. They are interested in whole personality. They see your academic record, extracurricular activities, essay SAT and TOEFL score. You have to do your best in all in these factor.

Yes, of course!

Technically, you can take the SAT as many times as you want. There are no restrictions for registering for and taking the test. There are 7 test dates throughout the year, so the only limit that stands in your way is time. You can pick and choose which scores from which test dates you want to send as part of your college application. Regards.