Rotom is the Sinnoh (platinum) region #152, obtainable in the Old Chateau at night (by interacting with the tv in one of the rooms)
In the sinnoh pokedex rotom is number 152 but in the national pokedex rotom is number 479 and chickorita is number 152
Rotom.
rotom
There is no number 152 in the Sinnoh Pokedex however number 152 in the National Pokedex is Chikorita.
Pokemon Platinum has two different Pokedexes: the Sinnoh dex and the National Pokedex. In the Sinnoh dex, #152 is Rotom. In the National Pokedex, it's Chikorita.
Rotom
Sinnoh Dex #152 -- Rotom National Dex #152 -- Chikorita
Number 152 is Rotom on platinum :)
Pokemon 152 is Chickoreta
Picachu
Rotom
The 152 Pokemon in the Pokedex is Rotom, not the other Rotom's just electric Rotom