[zedhed]

From the Sampletank Manual;
Activate the number of supported outputs according to the sequencer platform. A slider allows you to select the number of stereo outputs to be used by the module. This number may vary among the platforms. Once the slider is set to a value you’ll be able to set the desired out- put pair to the sequencer Mixing desk from the mix area, but only after closing and reopening SampleTank® 2. This is because SampleTank® 2 ‘declares’ how many outputs it will put on the mixer at the startup.

I haven't used Sampletank, but there should be an output selector on each stereo channel.

You'll need to create the required amount of Audio Tracks in Pro Tools then on the input selector of each track, choose 'plugins' and assign appropriate (corresponding with the outputs selected in Sampletank) channels to each track.

I'm assuming you're using Sampletank in Rewire mode.