Hi Imran,
I take it you mean free mixers? Preconditions: VBar NEO VBasic or VBar NEO Pro/+Rescue, or a legacy VBar 6.0, and the App NEO Macrocells, or Macrocells Old, loaded from the Shop App (Setup or Old Devices, respectively).
Then, you find the Macrocell sub menu in the Model Setup menu structure.
If you are looking for the Pro parameters (e.g. for fine tuning a helicopter), you'd need a VBar NEO with Pro update, obviously, and you find the Pro or Expert parameters just by scrolling down.
Kind regards
Eddi
Born to fly ...
forced to work.