A while back I had to un-deploy an old AD RMS deployment and then deploy a new AD RMS cluster. After deploying the new RMS some of the clients on the network did not have Permission (RMS) under the Options tab within Outlook. I narrowed it down to those clients that used RMS when the old RMS implementation was still in place. There is a way to reset these clients so that they can start over and connect to the new RMS server.
This can be done by deleting the old RMS reg key and removing some DRM files.
First on the client machine close out of any open Office programs such as Outlook or Word.
In the registry navigate to HKCU\Software\Microsoft\Office\XXX\Common\DRM and delete
Now navigate to %localappdata%\Microsoft\DRM and delete all files ending in .drm.
Once you have done this open Outlook or any other Office application and try securing an email or document. It should connect to the new RMS server and work.