The only way to get a Regigigas in Soul Silver is to trade it from a previous game.
First, get Pokemon Platinum. Get the special Lvl 100 Regigigas in your party* and go to Mt. Coronet. Then trade it to Heart Gold/Soul Silver. *The special Lvl 100 Regigigas is only available through Pokemon Events.
Regigigas is not in the actual game. You have to get it through a trade, a gameshark, an action replay, etc. Use google to find a code.
You can't catch charizard in Pokemon soul silver. You can get a charmander from professor oak.
Well You Can Catch:
its in mt silver.
sorry you have to trade it to Pokemon soul silver
No, you can not.
no
No
That's wrong you can catch regiice at sea foam islands after beating red and regirock at union cave and regi steel at mt. silver and regigigas at the kanto waterfalls you need all three though
you catch one in mt silver they are at level 50
you cant catch it in soul silver.