[JFreak]

Behringer ADA-8000 is not an interface. It is an AD and DA converter. You connect it to an interface. Protools should only "see" the interfaces and then the interfaces would use the Behringer.

So you have two 192's and one 96i as interfaces. It means you will need two HD cards, because one card can only use two daisy-chained interfaces. Third interface will have to be connected to second card. Then you need to set proper clocking (the "Loop Sync") between the three interfaces.

Once the interfaces are all set up, then you would connect the Behringer unit to the interface stack, whichever ADAT ports you wish to use. The Behringer should slave clock to the interface either via ADAT or Word Clock (better option).