I am not certain if NIS comes as a rpm package for you too remove...If you installed it by mistake and have not tried to configure it...I think you will be safe. You might want too disable the NFS service to be extra sure. As root:
type: chkconfig NFS stop
This is will stop the NFS service from running in run level 5 and 3.
I hope others will add to this...I don't want to miss lead you.