you can only get it two ways, you can either cheat or transfer from Pokemon colluseum.
Ho-oh is unobtainable in Platinum.
there is no ho oh or lugia event in Pokemon platinum
you cant get him in platinum
you dont
no
no
You cannot catch Ho-Oh in Platinum, you have to trade with someone with a HeartGold or Soulsilver. Another way to get a Ho-Oh is to migrate from a previous generation game if you have one.
You can't catch Ho-Oh in Pokémon Platinum, you need to trade it from Pokémon Colosseum or with someone who has it.
you can't get ho-oh in Pokemon platinum only by cheating with AR or r4 or migrate it of Pokemon gold
Ho-Oh can't be found on Platinum. The legendaries of Articuno, Moltres, and Zapdos can be found though.
you can only get it in Pokemon gold
You cannot find Ho-Oh in Pokémon Platinum because he is not available in it, so you need to migrate it from the gameboy games.