Celio is not a character that appears in Pokémon Ruby instead he is a character that appears in Pokémon FireRed and Pokémon LeafGreen he appears in the Pokémon Center on One Island and is in charge of the Network Machine you as the Player Character are required to find the Ruby and Sapphire items in order for him to finish work on the Network Machine so that your games can trade with games such as Ruby, Sapphire and Emerald.
give it to celio
You give it to Celio
Give it to Celio on one island.
You find the ruby and give it to celio
find the ruby and give it to celio.
Talk to celio in 1 islnad and he will ask you to get a ruby. The ruby is in 1 island inside MT.Ember.
beat the elite four with 60 owned Pokemon in your pokedex. celio will not tell you to get the ruby and Sapphire until u do
give it to celio who is in the pkmn center on 1 island
You also find the sapphire and give them both to Celio.
beat the elite four
You can do this after you find the Ruby and the Sapphire for Celio in Pokemon FireRed. then you can trade with Ruby, Sapphire and Emerald.
Yes if you give Celio the ruby and sapphire he connects with Lanette and all Hoenn trainers this means you can now trade between ruby, sapphire and emerald and even Pokemon colosseum and Pokemon xd gale of darkness.