The MBHO 603A is a microphone that consists of the body and capsule adapter:
So you need one of the following:
- The 603A body between capsule adapter and MP6 (biggest and most expensive solution to your problem).
- IPA, PFAs or NBox (I've heard rumours that there's a version that supports MBHOs) to power the capsules.
You can't just run the capsule directly into the MP6. The capsule requires polarization voltage, not phantom power.
Since you'll be running a MP6 that can provide 48V phantom power, my suggestion is to get PFAs that will convert the phantom power to the proper mic polarization voltage.