Your wireless network at office or home may have MAC filtering enabled then to connect to wireless network you must need wireless MAC address of your PlayBook device, so follow the given steps to find MAC address on PlayBook tablet.
On PlayBook home screen, tap Settings icon on status bar
Tap WiFi on the left menu
At the bottom of the screen, tap WiFi symbol icon with “?” mark on it
Here you can find MAC address named as Physical address. Use this Physical Address of WiFi Adapter and add it in your wireless router MAC filtering setting.