Is there a way that once a certain number signup using my registration form the registration form will shutdown?

is there a way that once a certain number signup using my registration form the registration form will shutdown? 

Yes, it is possible to disable the form once the limit was reached. You can change this option in the Form Settings, here's how:

1. In the Form Builder, click "Settings" in the top menu. Go to "Form Settings" and then click the "Show More Options" button.

2. Change the Form Status to "Disable on submission limit". After that, you can specify the number of submissions and the warning message.

Related guide: https://www.jotform.com/help/137-How-to-Limit-Submissions-in-a-Form.

Hope that helps. Thank you.