Vray to MtoA?
 

I have seen free models, i'm looking for forest type models, around but most say they are "VRay". I'm still new to all of this and i am assuming Vray would need to be converted to MtoA. If i'm wrong in my thinking please correct me.

Is their a program to convert VRay to Arnold?

Thanks

Models are just geometry. What engine can render them would depend on what kind of shaders are applied. Just swap out the Vray lights and materials and for arnold ones.