Rift : How do you enable FFA looting in group for dungeons?

[Alge]

You don't (or can't). Instead, you can check which character has loot rights by mousing over the corpse and looking at the tooltip. But there is no need to switch to that character. You can target the corpse on your main and move slightly past it, assist and then interact (using an in-game macro with just the text "interact"). Any character with loot rights will then loot without you having to switch screens.

[Mystic]

Excellent tip on the loot via assist/interact. I seem to recall doing that in WoW boxing the quests where the quest item drops for everyone in the group. I had forgotten about that trick entirely. Thanks muchly!