With the 6i6 this should be able to be done with a combination of the Output Ports selected for the tracks in PT and the mixer routing in the Focusrite mixer.

Route the drums to a separate Port from everything else (right-click and select Port).

You may have to enable the outputs first using Audio-Prefs- Drivers Button.
This enables various Ports, then you can assign a given track to an available Port using the right-click - Port option.

Keep in mind, once multiple ports are enabled you can also take advantage of them using the lower right hand setion of the mixer .. so you can send multiple tracks to a separate audio port and control the volume of these using the assigned slider in the lower right section of the mixer. (Normally used for Subgroups but can also be assigned to physical Audio Output Ports).

I see you are from Troy.
I used to be in Troy quite often. May be starting that again soon (we have a location there where I work, sometimes they need me there).
Don't really want to drive there much this time of year though; it's brutal cold tonight!
smile

I do not work here, but the benefits are still awesome
Make your sound your own!