Hi

One can give JEE Mains entrance  examination  for a maximum of  3 consecutive years  starting from the year of passing 12th board examination.

Now,

JEE Main entrance examination  is conducted twice a year i.e

*January session  and

*April session.

So,  the maximum number of attempts for jee mains entrance examination

= 2 times *3 years

=  6 attempts in total

So, one has a total of six attempts over 3 consecutive years  starting from the year of passing 12th board examination.

So if you passed your 12th board examination in 2020 you were eligible for JEE mains 2020 and you will be eligible for JEE mains 2021 and jee mains 2022 , now as Jee mains is conducted twice a year so you have 4 more  attempts left

For detailed information go through

https://engineering.careers360.com/articles/jee-main-eligibility-criteria

JEE ADVANCED

One can give or attempt  JEE Advanced for the maximum of two times and that too in consecutive years starting from the year of passing your 12th board examination

So if you've passed your 12th in 2020 you were eligible for JEE advanced 2020 and will be eligible for JEE advanced 2021

Thank you