hello hemant,

Online availability of application form for April is February 8, 2019.

you can check here all details about the date for April -

https://engineering.careers360.com/articles/jee-main-important-dates

Hope this is helpful for you.

Thank You.

Now that it is conducted two times an year. 

if you are asking for the april examination application form keep checking the website

the form will be available during the end of january or starting of february but keep checking. 

JEE Main Application form of April Session is expected to release on 8th February, 2019. You can check the other information about with the given below link.

https://engineering.careers360.com/articles/jee-main-application-form

Good Luck!