Which route is Pichu?

Pichu is not a route in any video game or other media.

Perhaps you are thinking of:

* Route 2 in Pokémon Gold, Silver, and Crystal: This route features a Pichu encounter.

* Route 39 in Pokémon HeartGold and SoulSilver: This route has a chance for a Pichu to appear in the wild.

Could you please clarify your question? 😊