you need an interface with independent headphone outs or with enough extra outputs to accommodate custom mixes within your DAW.

My Focusrite red4pre can do custom headphone mixes in the focusrite control software.

the second option is how i would do it in my studio. create a submix in your DAW and send it out output 3-4, and do the same for output 5-6. (or 1-2 and 3-4)

you could probably power the headphones with just the line outs (with something like this - https://www.amazon.com/TNP-3-5mm-Stereo-Breakout-Adapter/dp/B079JQQSCC), or get headphone amps (or whatever else you have).

I wouldn't spend a bunch of money on an interface with features you don't need just for independent headphone outs. i'd go with the second option, personally.

you could technically pull it off with the 2i2 and make mono submixes. send one out 1 and the other out 2. you'd probably have to make custom cables so you can split off the hot signal to both sides of the headphone, otherwise you would be sending the (+) to one side and (-) to the other of the same signal as the output is balanced. it would sound weird and phasey.

hope this helps!