@vlada - sure. Kontakt is able to internally route things to up to 64 outputs - not talking about Sonar here - I mean that within Kontakt, you can have up to 64 outputs. I myself do not use more than 16 outputs per any one instance of Kontakt, but in any case the process is the same.
1. Insert Kontakt (I usually pick the one with 64 outputs). I do NOT let the insert soft synth dialog box create and assign my audio tracks or midi tracks - I choose to do that manually. I do it this way because of how I end up creating the multiple outputs for multiple loaded instruments, as described in the next steps.
2. Load several instruments into Kontakt (Piano, Bass, Organ, Rhodes)
3. Click on the button at the top of the window that turns on the Output Section to become visible at the bottom of the Kontakt window.
4. Now, in the Output Section, there is a drop-down arrow next to where it says 'Presets / Batch Configuration'. Click that arrow, then hover on Batch Functions, then click on the one that says "Clear output section and create one individual output channel for each loaded instrument". This wipes out the default outputs and inserts a stereo output for each load instrument, naming each to the same name as each instrument's preset name.
5. I happen to want to rename those output channel names to something better, so I always rename them to be for example 'Piano', rather than 'Bechstein Bach', etc. So, I would end up with output channel names like, Piano, Organ, Bass, etc.
6. Now, I insert one midi track for each loaded instrument, so if I have 4 instruments I would insert 4 midi tracks, I also name each midi track to something like Piano Midi, etc. I also set each midi track's Output Midi Channel to match the channel assigned to that instrument in Kontakt. (each time you load an instrument in Kontakt, it automatically increments the assigned midi channel for the new instrument, so the first loaded instrument is defaulted to midi channel 1, the 2nd loaded instrument gets midi channel 2, and so on. The Midi Output for each of these midi tracks is also simply assigned to Kontakt.
7. OK, now for the audio tracks. I insert pairs of audio tracks for each loaded stereo instrument, such as keyboard instruments, and a single audio track for instruments such as bass. I then assign left and right outputs from each instrument to left/right mono tracks as appropriate, and for mono instruments I assign to left mono channel. I also name the audio tracks to be something like, Piano Left, Piano Right, Bass, organ Left, Organ Right, etc.
So, that's how I do output routing assignments using Kontakt with multiple loaded instruments in Sonar.
Bob Bone