Chansey is found in the safari zone only.
It is believed that Chansey is the rarest Pokemon of all to catch in Pokemon FireRed and LeafGreen. It can only be found in the Safari Zone, near the north half of it.
Chansey can only be found in the safari zone, but it is very rare, and even when you find it, hard to catch. I do honestly wish you good luck, because you are really gonna need it.
Wild Chansey are found in the Safari Zone. It's a rare encounter and is difficult to catch, along with the fact that it can flee at any time during the encounter.
Chansey can be found in Mauville City Gym map.
Chansey may rarely be found on Routes 13, 14, and 15, which are found east of Fuchsia City in Kanto. Kanto can only be accessed after beating the Pokemon League.
you breed a chansey which are found in the trophy garden
Growlithe is found in the Pokemon Mansion on Cinnabar Island in Pokemon Firered.
Celebi cannot be found in Pokemon FireRed. The only way to get Celebi in Pokemon FireRed is receiving it from an event distribution. These events are sadly no longer supported for Pokemon FireRed.
Yanma can't be found in Pokemon FireRed or Pokemon LeafGreen; it is strictly a fourth generation Pokemon.
Nidoran Male and Female can be found in these places: The route west of viridian city and the safari zone.
Teddiursa can't be found on firered trade one from emerald to firered.
There is one King's Rock to be found in Pokemon FireRed in Sevault Canyon. They can also sometimes be found on wild Pokemon like Poliwhirl.