10
Try
$sql = "SELECT u.uid, u.uname, u.user_avatar, p.country, p.field1, p.field2 FROM ".$xoopsDB->prefix("users")." u
LEFT JOIN ".$xoopsDB->prefix("groups_users_link")." g on u.uid = g.uid
LEFT JOIN ".$xoopsDB->prefix("profile_profile")." AS p ON u.uid=p.profile_id
WHERE g.groupid = 6 AND u.level > 0 AND u.uid NOT IN (1) AND u.user_avatar <> 'blank.gif'
ORDER BY RAND() LIMIT 10";
field1 and field2 are to be replaced with the real profile names.
(It is assumed that the fields may be visible to all groups.)