exporting 3ds max

i have created 3ds max model and to make it smoother i used the the NURMS property of 3ds max but when i exported it to unity the the NURMS was not included? how will i include the NURMS to make it smoother in unity?

Put an Edit Mesh modifier above the NURMS mod, if that doesnt sort it you will need to convert the model to EditMesh prior to exporting