You can transfer to another entity at the same location if: (a) You are able to board it, or (b) Your entity and the other can share sensors (see Scanning: Sharing Sensors), or (c) The materials and the entity are owned by the same character or faction.
My question is about (c)
I am at a station trying to load RMs which are owned by the station owner but i am not assigned.
If i read (c) right shouldn't i be able to load the RMs even if i am not on the crewlist or assigned to the station?
Crewlist at the minimum is enough, regardless of ownership or the like, for the purpose to unload from your own ship/entity into another entity/your destination.
Its only when you are boarding an entity from which you are going to unload from, yes, you will need to be assigned pilot/operator, in order to access the control room.
Additionally, the same applies when it comes to construction of stations and entities, if the materials are aboard your ships and someone else is the builder, you need to ensure the builder is crewlisted onto your ship and the materials are in the builder's ownership (usually their faction in this case). They do not need to be aboard your ship or anything like that, just need the crewlist access.
(Same again for NPC builders if you are supplying them, they need only be assigned to the builder/(faction), long as they also have crewlist access to the ship for which the NPCs are aboard)