If I understand, you need to import it in archicad, wich is Bim. Using dwg or fbx, you loose bim information. In this case, IFC is the format. You need to export it from revit, and import from archicad. It will preserve information related with geometry and bim, in order to edit it in archicad. I have revit, so I can convert it for you if you want, altough, I don't have Archicad, I can't test it. Good luck.