That looks like it only supports a so called 6to4 tunnel. (in short: proto-41 tunnels, but using 2002:aabb:ccdd::/48 as address space, where aa.bb.cc.dd is your IPv4 address). Theoretically you don't have to configure anything else than the options given there, stability is something that might magically work perfectly or absolutely not depending on your relay and the path between you and that relay, that relay and the remote site and more importantly the path back. The IETF has moved towards deprecating 6to4 for a stability reasons and the amount of needless debugging that it requires due to the many many pitfalls the setup has. SixXS does not support 6to4 as it is in a way an anonymous access protocol and does not give you any guarantees of path or performance, we do provide static and heartbeated proto-41 tunnels though. As it looks like there is a drop-down option, maybe there are other better suited options there?

The Other Options are Called "Pass Through", "Fixed", "DHCP", "PPPoE" and Autodetect all of witch seem to be for a Dual Stack Connection... So if i want to use a 6to6 tunnel...where should i register? any ideas?