Hi Aspirant,
It all depend on the state board which you want to appear. If you have already taken admission in 11th 2020 in state board, then it is easy to appear for class 12 again in 2022. But if you are talking about directly taking admission in 12 and appearing for exam in 2022 then it's difficult to switch over the board of education.
If you are doing this to improve your marks, then you can do so by giving exams through National Institute of Open Schooling (NIOS). Refer the links below to know more about NIOS,
https://school.careers360.com/exams/nios-class-12
https://nios.ac.in/
Hope this helps.
All the best!!!
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