He's in Eterna City.
>Eterna Condominiums In this building, Sinnoh's Name Rater can be found, as well as a person named Norton who will trade a Chatot for a Buizel, and yet another who will give away TM67 (Recycle).
Sources: Experience Bulbapedia (In case you want solid proof)
Hope I helped!
He is in eterna city.
