In Ruby, Sapphire, or Emerald, never.
In FireRed or LeafGreen, after you have defeated the Elite Four and have 'dex entries for at least 60 Pokémon.
You need to beat the elite four and get the national dex then talk to celio.
Get the National Dex. You can do this by catching 50 different kinds of Pokemon (give or take a little.) Then, just go to One Island and visit him.
but before this, you must have defeated the elite 4
beat the elite four
fight him ye i trick yu
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
After beating the elite 4 and obtaining the national dex head to one island and talk to celio he will mention the ruby now go to mt ember to get it.
Celio González was born in 1924.
Enrico Celio died in 1980.
Enrico Celio was born in 1889.
Celio - retailer - was created in 1985.
Celio Calcagnini was born in 1479.