Restoring a course in Moodle first of all depends on your account permissions.
If you are an editing teacher of a course, you are able to restore a backup file either into one of your existing courses, or into a new course that will need to be created for you by an administrator or course creator.
If you are a course creator on the Moodle site, you are able to restore a backup file either into one of the existing courses, or into a new course, which you can dynamically create during the restoration process.