Hi

You will have to fill the online application form to register for JEE Main exam. Following the last year trend, the application form of JEE Main can be expected in the first week of December 2017. The last date to fill and submit the JEE Main application form will be tentatively in the third week of January 2018. I would suggest you to first check the complete eligibility criteria of JEE Main and then fill the application form. 

You will have to provide your personal and academic details in the application form along with uploading of your photograph, signature and thumb impression, followed by payment of application fees online. 

You can check the eligibility criteria from the link given below:

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

You can track the application form from the link given below:

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

All the best!

The registration of JEE Main application form is expected in the first week of December, 2017. To check the application procedure you can go through with given below link.

JEE Main Application 2018

In case if you have any query let me know.

Good Luck!