Unfortunately, the NXC controller is an older generation and doesn't support MotoPlus API on which the ROS driver is built.
For a controller of similar size to the NXC, you would need to get the FS100 controller with a new robot.
Otherwise, for remote controller of the NXC you can use the "Ethernet Server function" or MotoCom API (for Windows).
In theory, you might be able write a ROS driver to send motion instruction through the "Ethernet Server" but there are limitations.
Communication response is fairly slow (around 60 ms) and you can only queue one motion at the time, so the robot need to reach its set destination before you can send the next destination.
If you are interested in the "Ethernet Server", contact Yaskawa Motoman customer support in your region and ask for more information.
Yaskawa America Inc
Motoman Robotic Division