Hello ambarish ,

First you will want to verify if your devices support WiFi 6. Once you have verified that, the best way is to do a speed test. If you are getting over 500 Mbps you are most likely on WiFi 6 as WiFi 5 generally doesn't go over 500 Mbps. But every device will be different in terms of availability of information on how they are connected. iPhones for example do not allow you to see this. The eero app also does not show this information.

Something else to keep in mind is that the devices themselves decide on how and where they connect.