1. Remove from device.

lsattr -El lo0
chdev -l lo0 -a netaddr6=''"
ifconfig -a
ifconfig lo0 inet6 ::1/0 delete
ifconfig –a

2. Remove IPv6 from net services file /etc/netsvc.conf.

Edit /etc/netsvc.conf
The default, on AIX, is thus:hosts=local,bindReplace this with:
hosts = local4,bind4