Only superusers can remove OUs from Isora GRC.
Go to the Organizational Units section of the Settings page. Locate the OU you want to remove in the table and click the trash can icon next to it. You won’t be able to remove an OU that has children.
Click delete to confirm.
Removing an OU will also remove all permissions any users may have had within that OU, but it won’t remove any people.