Hello aspirant,

Since you are clearing your 12th Boards in 2021, you are definitely eligible for JEE Mains in 2021. Here is the list of eligibility criteria:

• There is NO age limit
• The candidates should have passed their class 12 ^th or equivalent exam from a recognized university with Physics and Mathematics as compulsory subjects along with one of the Chemistry/ Biotechnology/ Biology/ Technical Vocational subject.
• The applicants who have passed their class 12 ^th exam or its equivalent in the year 2019 or 2020 or will be appearing in the qualifying examination in the year 2021 are eligible to appear in both January and April exams.

Hope this helps you.
All the best!