Hi

No, you won't be eligible for jee advanced 2021

This is because,

One has a total of two attempts for JEE advanced over two consecutive years starting from the year of appearing for 12th board examination i. e as per , eligibility criteria one is eligible for JEE advanced examination only in the year in which he or she appears for 12th board examination and the next year following it. So, to be eligible for jee advanced 2021 , you must have appeared for your 12th board  examination for the first time in either 2020 or in 2021.

You can check the same on the page number 11 of jee  official information brochure, the link to download it is provided below :-

https://jeemain.nta.nic.in/webinfo2021/File/GetFile?FileId=1&LangId=P

Now,

Though you failed in 12th in 2019 and passed in 2020 , your 12th appearing year for the 1st time still remains 2019.

So, with 12 th appearing year as 2019 , you were eligible for jee advanced 2019 and jee advanced 2020 only.  Thus, not eligible for jee advanced 2021.

You can check detailed eligibility criteria of JEE advanced by visiting our page the link for the same page is provided below

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

If you have any other doubt then you can always reach us to clear them :) we are always available to help you out and guide you

Thankyou