A:Answer Any new router with WiFi 6 (I assume that is what you mean by T6) will be backward compatible to 2.4 GHz. This thermostat uses 2.4 GHz because it needs the longer distance of 2.4 GHz. Pretty much all Internet of Things appliances like thermostats, doorbells, refrigerators, washers & dryers, garage door openers use 2.4 GHz because they send small amounts of data, but they do need a larger distance coverage.