My name is Roberto Flores and I work for Ruckus support. There is a way to get the IP address of the ZD. The ZD by default has UPNP enabled. This means that if you connect a laptop to one of the ports of the ZD, the laptop will get an IP address from the same network that the ZD may reside on. Then you can open a Windows folder (using a Windows machine) and click on the Network option (Id don't know the Apple option of discovery and thus referencing a Windows client). It will discover the ZD IP address.
Now, once you have the ZD IP address, you would have to login. You would need the username and password. If you don't user/password then if the previous folks left you a debug info file or a backup file of the controller, Ruckus support can extract the password from decrypting the file. You can provide us with the file via a new post.
The last option is to factory default the ZD for which the IP address would be 192.168.0.1 with user/password = super/sp-admin (respectively).
You can get the manual and quick startup guide for the Zone Director controller from your Ruckus support portal (https://support.ruckuswireless.com)