@Kevin_Z Thank you Kevin.  Yes it is EU version.  However Europe show allow no only Band 1.  Why is TP-Link limiting it to only Band 1 but not specifying this in the manual or anywhere else.  Disappointed.

Is there anyway I can flash the US version firmware or enable more bands?

@Tin 

Tplink should specify that c6 only support band 1 in 5ghz.
It can not be expected from tplink. if i knew that i wounld never buy c6.
I will never buy tplink router in my life. All the higher-end router like c9 support band 4 in 5ghz wifi in all regions. So region lock is just an excuse from tplink.
Even their c60 lower-end router support band 4 5ghz in all-region.

so pls stop excusing saying about region lock. 
Just disappointed from tplink, regret to buy c6.

I think this is a legal issue. The old TP Link routers which were released before 2016 had a region change option and the firmware was universal. If you set the region to US you had access to the higher channels. But now, the new TP Link routers have separate EU and US models with their own firmware, and so what you see in the channel list is what you get.

https://www.extremetech.com/computing/224611-faced-with-fcc-regulations-on-router-capabilities-tp-link-blocks-open-source-updates

Not sure about other router manufacturers, maybe they do the same thing.

@netcrypt9119 fixing the region may be a regulatory requirement.  However limiting to band 1 only is not.  C60, C7 and C9 etc have more than Band 1.  Why C6 only had band 1.

@Tin You can go to tp-link international website at https://tp-link.com/en (as they have EU firmwares instead of US ones) and check the emulators for the latest hardware revisions like C7 V5, C60 V3, C20 V5 etc. The V1 models may have the region change option if they were released before 2016 but because the newer revisions were released in/after 2016 they only have 36 to 48.

I used to have Archer C20i UK model before, and the firmware was universal. This router was released in 2013. It had the region change option and the channels 149 and up. But after applying the firmware released in 2016 which was for regulatory certification, the higher channels and region change setting was removed.

@Tin I live in Europe and I see plenty of routers that use ABOVE channel 48. In fact, when I first plugged in my Archer C1200 it could go all the way up to 128. So something is definately not right. TP-Link didn't program their routers per country, but they instead cheaped out and just made general rules.

A quick example; These channels are allowed in Denmark. You can clearly see the bandwidth etc. via green colors.

I personally use 40mhz, so I should be able to select above 48 no problem. However ......

@vBDKv yes, I have read similar articles.  More channels should be allowed in Europe.  TP Link engineers are just too lazy to get the best out of their products for their customers

Tp-link just does not care about customers. After sales support is unknown to tp link.

Here's a good example of a wave 2 router (!!!!) sold with only 4 channels enabled: to wave 2 or not to wave 2

Years later - " please do not worry, we use the chip which supports 802.11ac wave2. While the firmware to support 160MHz has not released yet that is why you can not see it now".

Someone is having fun.