You can follow the below steps to retrieve the Playlist.
1. Open \appdata\roaming\Real\RealPlayer
2. Copy “db” folder to desktop
3. Perform clean uninstall and re-install of RealPlayer Cloud by following the article:
4. Reimport all the media files
5. Open \appdata\roaming\Real\RealPlayer again
6. Rename the existing “db” folder as “db.old”
7. Copy the “db” folder from desktop into \appdata\roaming\Real\RealPlayer
8. Open RealPlayer Cloud. Playlists will be back.
Note: Generally, if the playlist is deleted then it cannot be retrieved.