I'm a bit confused myself, without StratOps to reference. AFAIK from discussions with the MegaMek devs (having recently implemented such rules), you can drop one 'mech per door per turn. Not sure where this 'one per six' is coming from, unless the 'one per one' is space turns, which would imply 1 per six for ground turns, meaning either way it takes one minute to drop a 'mech.
Of course just to make things confusing, Tech Manual says you can drop two mechs per door per turn.