you get TOGEPI
You see Cynthia many times in Pokemon platinum. She gives you an egg containing a togepi in eterna city. She also meets you on your way to meeting and catching giratina. Also, if you defeat the elite four, you battle her for the title of Pokemon champion.
In the Eterna gym in eterna city.
Eterna City
She gives you the Togepii egg when you have beaten Team Galactic in Eterna City when you head towards the bike shop to get your bike
in eterna city
it's between Eterna Forest and Eterna City
hearthome city
Eterna City.
South of Eterna City.
its in the egg Cynthia gives you in eterna city
At the end of Eterna Forest, right before Eterna City.
At oreburgh city up to eterna city