Rings and tribes are an alternative to the existance of Clans that allow people to
form a guild without meeting the requirement to become an official clan. As none of
these are official organizations, their bennefits are quite limited, but those which
grow enough they might apply to become an official clan.
A ring can be forged with 10 people and 500,000 coins which has limited clan functions to
help it grow. When the ring grows in size to 50 people it can be upgraded to a tribe
which includes even more expanded clan functions. When the tribe has 100 members it can
apply for official clan status with the appropriate kingdom tribunal.
To start a ring visit Rotah in the wilderness village, north of Koguryo entrance. Be
warned that those who are members of rings or tribes are not able to join official
clans or an army and must live in the
Wilderness.
For not being official Nexus organizations, their lists are not available in KRU's
community page. Here's a list of the majority of rings and tribes, since it's not
possible to keep track of all, as they're formed and destroyed without much
information.