PS3 uses the 4-4-4 code on PSN Redeem. the 6-3-6-3 is for separate Square-Enix Membership (social profile) which isn't at anyway tied to Square-Enix Account for FFXIV service account.

When you run your PS3 game client, you will be prompt to use your SQEX login, which at the first time login, it will tie your SEN to SQEX.