With #1 piston up as indicated by the crank pointer you are either on number one or you are on number six. if you were to rotate the crank 360 degrees you would be on the other.
Since the cam aligns as Arthur states your question then comes as to where to put the distributor.
To tell whether you are at one or six look to the lobes of the cam on these two cylinders. The one that has the lobes up (rabbit ears) is the firing cylinder. The one with lobes down is not.
Bosch Master, ASE Master, L1
33 years MB technician