Edit role's permissions

Permissionmember
Organic groups
Edit group
Edit the group. Note: This permission controls only node entity type groups.
Administer group
Manage group members and content in the group. Warning: Give to trusted roles only; this permission has security implications in the group context.
Organic groups UI
Subscribe to group
Allow non-members to request membership to a group (approval required).
Subscribe to group (no approval required)
Allow non-members to join a group without an approval from group administrators.
Unsubscribe from group
Allow members to unsubscribe themselves from a group, removing their membership.
Approve and deny subscription
Users may allow or deny another user's subscription request.
Add user
Users may add other users to the group without approval.
Manage members
Users may remove group members and alter member status and roles. Warning: Give to trusted roles only; this permission has security implications in the group context.
Add roles
Users may view group roles and add new roles if group default roles are overriden. Warning: Give to trusted roles only; this permission has security implications in the group context.
Manage permissions
Users may view the group permissions page and change permsissions if group default roles are overriden. Warning: Give to trusted roles only; this permission has security implications in the group context.