6-3-6-3 code is for your Square-Enid Membership, which is not the same for Square-Enix Account for your service account. The PS3/PSN redeem code is used to attach the game to your SEN, and when PS3 cgame client launch the first time, you will need to create/login to a service account and then the PS3 game client will then tie your SEN to SQEX, which then will show up in Square-Enix Account/Mog Stations.

6-3-6-3 code is to add game registration for your Square-Enix Membership "Social" Profile.l