Hi Dear,

You can apply for JEE Mains when you  are appearing for your class 12th Examination or any equivalent qualifying examination or after completion of your 12th class. The application form is to be submitted online which is generally started in month of april or may every year.

For more details visit:

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

Good Luck

JEE Mains is conducted twice in a year. Once in January and once in July. So if you are either in your 12th or have completed your 12th with Physics, and Mathematics as compulsory subjects along with Chemistry or any other vocational subject, then you are eligible for JEE Mains. For the year 2020, the registrations have been completed and so you cannot appear for JEE Mains in 2020. You have to wait until the official notification is released for January 2021 session and then register.

JEE mains 2020 registration window has been closed. Youu can apply for JEE mains 2021. The dates are not yet been declared. You can stay tuned with the official website to know the details. Usually the dates will be around from February to March for JEE paper.

Best wishes. Thank-you.