Hi Ronald,
MQTT is a software platform and doesn’t need coordinators.
Could you please clarify what you are doing and what your question is about?
I’m guessing this is dealing qith something Zigbee, Zigbee2MQTT or ZHA possibly?
A Zigbee network can have only 1 device acting as the coordinator.
Maybe some of this can help clarify things for you?
The Home Assistant Cookbook - Index.