There are several things that need to be in place for the Stagebox option to show up:
1) The AI Console must have an AVB option card installed. The I/O card that comes with the RM mixer is an AVB card, but the one that comes with the AI Consoles is not
2) The AI Console must have an AVB capable connection to the RM mixer. This means either a Direct Connection** to the RM mixer with a single ethernet cable, no switches or routers in between, OR the AI Console and RM mixer must both be connected to an AVB switch.
**For Direct Connect to work without having Wifi Adapters in both mixers, you must also be on the latest release Firmware (7049 for RM, and 7045 for Consoles). The RM mixer will still require a Wifi adapter and a wifi network to connect to though, as it functions as your Monitor Mixer, and you need a way to control it. It's for this reason that we only recommend using the AVB switch setup.
3) You have to first make sure that the AI console sees the RM next to "Available Devices:" and is showing as connected to the RM mixer next to "Connected:" on the Last page of the System menu, before the Stagebox option will show on pg. 6