you get it in tyhe water route on the way to pal park
you can not capture it in Pokemon diamond you have to migrate it that isn't true.... i caught it is Pokemon diamond and pearl so migrate isn't the only way... you can catch it on route 220 with a superrod after you get the national pokedex
Chinchou is not available in Pokemon Firered Version. You can only get it by trading from Pokemon Ruby / Sapphire / Emerald Version.
You can capture a Chinchou in Route 210 with the Super Fishing Rod. It is quite common, for it appears with a 30% chance.
you can find chinchou in variuos places inside Mt.Coronet
lanturn