Rotom is no. 152 you have to go to the TV in the Old Chateau at night and bump the TV Rotom will come out and battle you at level 20.
Number 152 is Rotom on platinum :)
There is no number 152 in the Sinnoh Pokedex however number 152 in the National Pokedex is Chikorita.
In the sinnoh pokedex rotom is number 152 but in the national pokedex rotom is number 479 and chickorita is number 152
rotom
For the Sinnoh Pokedex: Rotom For the National Pokedex: Chikorita
Rotom
Rotom.
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.
152: rotom (platinum pokedex) 152:chickorita (national pokedex) you can catch rotom when you examine the tv in old chateau between 8pm and 3:59am
Rotom is the Sinnoh (platinum) region #152, obtainable in the Old Chateau at night (by interacting with the tv in one of the rooms)
The 152 Pokemon in the Pokedex is Rotom, not the other Rotom's just electric Rotom
Rotom: Old Chateau, night only