There is no particular is decided for SAT it is dependent on the candidate who is willing to give exam. Many students after 10th that is in class 11th give the exam and if they are not selected then they have another chance to give the exam. Time to write the SAT paper to Indians is the December attempt which they can give in class 12th.
For more information related to SAT exam you can go to the link given below.
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All the best for your future!