Hello Shaswat,

CA foundation is a kind of enterence test for for student who want to do CA as a career option from some top most institute in india. Once the registration is done for the Foundation course it will be valid for three years. But Registration in the course is not enough to appear in the Foundation exams. You have to fill the exam form to inform the ICAI that you are appearing in the Exam.

Thank you .

Hope it helps.