@Kevin_Z Thanks for your response.
 

Who is your ISP, please?

- Well I am using a local ISP. I don't know how to know the mother ISP name.

Is the IPv4 connected fine?

- Yes that's what I am using to reply to you.

Are all the parameters for IPv6 confirmed to be correct, such as Get IPv6 Address: SLAAC? Please try choosing Auto.

- I tried

-Auto- No IPv6 Address

-SLAAC- No IPv6 Address

in both options it's not working. doesn't matter what I choose it's not getting IPv6 address. I asked the ISP they said they use SLACC or Bridge and it works like charm. But something with Archer C6 that it's not working here.

What do you mean with 'plain' ipv6? Im using DHCPv6 they assigned a static /48 for every customer. I also had issues with IPV6 while I was using my UDR before and I believe I also had to solve it with creating a manual IPV6 route. But filed a bug and after a few releases they solved the issue. So hopefully it can do the same.

  @hrwe Hi, mine is shared broadband internet. So, no Dynamic IP. ISP asked me to select SLACC or Bridge, mainly SLACC does the job. But in my case my IPv6 section there's nothing. it's blank in the IP section where it should show me the IPv6 IP address.