Dear Shilpa
Try to click on the payment option which will be at left 3rd and if problem doesn't solve,  you have two options:

• You can reach JEE main team, by using contact us in the official website
• Or else you can wait for January 4th week, at that time if you are application is having any errors you can correct it.

All the best.

It means that you have uploaded your photograph and signature.Now you can proceed to third step i.e. payment of application form fees....
Do it before 2nd January 2018.After doing it if you want to correct yourvuploaded image then you can do this in January when cbse will provide a link for correction on jee mains website.For more details you can contact jee through email or telephone numbers.
All the best!:)

Ok. Have you tried this? Check the menu on the left hand side. It says third step is payment. Click on that and you should get the payment window. Let me know if that works.