I know you're a new member, but a few pointers for next time:
-This fourm is for Bulbapedia discussion only, the wiki; questions relating to the games probably should go in the Pokémon Games section.
-In the Pokémon Games fourm, there's a thread for misc. questions.
And while we're at it, might as well answer the question:
As far as I'm aware of: no. The guaranteed Red Gyarados in G/S/C is currently a one-time thing. The only way to obtain one is by catching a shiny Gyarados by the normal methods in R/S/E or FR/LG and trading to your game.
