MAC Address is a unique code assigned by the hardware manufacturer. If there is a wireless network secured by restricting the MAC addresses, your need to find out what your MAC Address is for registration on the Bluezone network. Here is the tutorial on how to find your MAC address on your Nexus 7 tablet.
* Press on the Home button to go to the Home screen.
* Touch Settings, and choose "About" at the bottom of the list.
* Touch on "Status", scroll to see the your Nexus's Wi-Fi MAC address.