You can take the SAT as many times as you want, but most students take the exam 2 or 3 times. Exam validity is 5 years, but schools do not look at your SAT score from the same perspective as 5 years ago. For this reason, considering the validity of the exam as 2 years, if you take the exam from the second semester of the 10th grade, your exam score will be valid until the applications. If you are not satisfied with your score, you will have time to prepare and retake the exam before the application deadlines.