First attempt - In the same year in which you pass your 12th board exams.
Second attempt - In the consecutive next year after your first attempt
Third attempt - In the consecutive next year after your second attempt but note that this is only for mains you're nit eligible for jee advance after the two attempts.
Hope it helps.
Thrice, once with your 12th boards, and two more times in next 2 consecutive years.
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