"At/on/in railway station" [duplicate]
Solution 1:
In addition to what @tunny wrote wrt on the platform and at the station:
In the station means that you are in the building that is at the station. If there is no such building, but only a platform, then using in is not an option.
At the station means anywhere in the close general vicinity of the railway platform(s). You could be in your car in the station parking lot, or you could even be a block away from the station, walking toward it.
Solution 2:
In British English, your are on the platform at the railway station