Can u explain it plzif modem doesnt supports it, but ISP supports it, then you can tunnel ipv6 over ipv4 through tunnel broker
here are some warious brokers around the world
https://en.wikipedia.org/wiki/List_of_IPv6_tunnel_brokers
What benefit do you believe you will get ?My ISP provides IPv6 but the problem is my router don't support IPv6 so is there any way in which I can use IPv6?