If the projectui module is installed, templates are only made available inside projects.

If you want to enable templates outside of a project (like folder is, by default), then you need to remove the projectui module but make sure the favorites (org.netbeans.modules.favorites) module is enabled for your suite.

To make your template available as one of the choices on the New File context menu (as opposed to having to choose the type in the wizard), then you have to list it as a privileged template.

See Tom Wheeler’s TodoListManager for an example of code that does these things.