Different Thrust settings

Hello,

am working on a project where we are building a Tilt rotor VTOL. There are total 6 motors. 4 are tilting and 2 non-tilting. There are total 4 servos for aileron and a V tail.
Rotor

Two motors near the CG (black dot) takes only 20% of MTOW and rest four takes 80%. And two motors near the CG runs only in till transition.

How to change throttle output in this proportion?

Which part of the code should i change?

Thanks in advance.