Zigbee network depends heavily on its mesh networking technology so best is always to try to have all your Zigbee devices connected to the same Zigbee network, (and Zigbee devices can only be connected to a single Zigbee network / Zigbee Coordinator / Zigbee Gateway), so I recommend using either the built-in ZHA (Zigbee Home Automation) integration or Zigbee2MQTT (Z2M) with ITead’s Sonoff ZBDongle-P (Texas Instruments CC2652P based) Zigbee Coordinator USB radio adapter which can work with either of those, (but note that it can not work with both at the same time and there is not easy or seamless migration between them). Check out therese community guides:
https://community.home-assistant.io/t/zigbee-buyers-guide/654695
https://community.home-assistant.io/t/migrating-from-a-philips-hue-bridge-to-skyconnect/620862
There are no guides or integrations yet for Zigbee support in ESP32-C6 as it is cutting-edge so currently only skilled C-developers with loads of time can use it via Espressif’s SDK → GitHub - espressif/esp-zigbee-sdk: Espressif Zigbee SDK