you can import rhinoceros files to the Creo Parametric. Basic license of Creo 3 supported this. Your model or assembly will be looks by surface models only but you can create thick and you can doing modifications of course..in flexible modeling for example...or you can save your rhino models like a IGS formats, it is your choice. I have some rhino models and i can imported it in creo without problems.
Business Continuity with Creo: Learn more about it here.