A better way to answer this is what Pokemon you cannotcatch:
I think that should be it. Most of these are Legendary Pokemon that are specific to certain games, so the only way you could get it would be to trade it from another game (and Pokemon like Leafeon and Glaceon can only be obtained by leveling up Eevee in places that don't exist in Soul Silver.)
However, the game has data for events dealing with Arceus, Jirachi, and Celebi, so it's possible that Nintendo may host events or promotions featuring these Pokemon, but it's currently not known if these events will happen outside of Japan.
austinb. here u can catch mew heres how
u go where u find and catch mewtwo, ceruleon city cave, u drop trhee rare candys in the same place as where u catch mewtwo have mewtwo as first Pokemon wait a day go back she should be there,
and u can get celibi but u need masterball
put masterball in shrine in ilex Forrest and wait
sorry you have to trade it to Pokemon soul silver
You can't catch charizard in Pokemon soul silver. You can get a charmander from professor oak.
you catch it in cerulean cave
you have to trade it from diamond to soul silver and you can't actually catch Roselia wild in Pokemon soul silver.
You can't catch Deoxys in soul silver
sorry you have to trade it to Pokemon soul silver
You can't catch charizard in Pokemon soul silver. You can get a charmander from professor oak.
Catch Pokemon
You can't catch kyogre in Pokemon soulsilver.
you catch it in cerulean cave
In johto!
snorlax
no you can, you most catch it in Pokemon emerald
you have to trade it from diamond to soul silver and you can't actually catch Roselia wild in Pokemon soul silver.
you can't catch it, you have to get it from an event which has passed
You can't catch Deoxys in soul silver
you cant but you can trade it from Pokemon soul silver