Hello aspirant, hope you are doing good.

So, as you might be knowing, you can appear for JEE Mains examination only thrice, successively. In those tree times, the first time is always the year when you are passing out. You didn't mention if this is your final year of school, i.e your class 12 boards are this year, then whether or not you sit for the exams this year, it will be counted as attempt 1, and you will have two more attempts left for you. You can definitely sit for the exams again next year.

Hope this helps you. Good Luck!!