Here is one thing. You can catch them in certain areas or find a friend who has Pokemon Leafgreen, Firered, Sapphire, Emerald, or someone who also has Ruby that can trade you some of those Pokemon if they have it. Another thing is buying a cheat. The cheat for the GBA will have codes to get any item or Pokemon avalible in the game.
All The Shiney Pokemon You Can Get In Pokemon Ruby Are All The Pokemon You Can Get in Ruby Any Pokemon Can Be Shiney Even Starters and Legendaries. So There Are 200 Shiney Pokemon You Can Get In Pokemon Ruby.
All the Pokemon past Turtwig are unavailable in Ruby.
pikachu
you dont go to jhoto in ruby
if you want to cheat to get all legendary Pokemon on ruby you have to play on the computer
You can find all kinds of pokemon.
OddishGirafarigDuduoNatuWobbuffetPikachuGloomPsyduckSeakingGoldeenGolduckXatuHeracrossPhanpyGeodudeMareepSunkernSpinarakAipomHoothootGligarSnubbulStantlerMarillWooperQuagsireMagikarpRemoraidOctilleryTeddiursaLedybaPinecoHoundourMiltankShuckleThat's all of them :)
catch all Pokemon
catch em all or dont
All in pokemon centers upstairs
You get the diploma from catching all Pokemon from Nationaldex and Hoenndex.
Pokemon ruby's version IS Pokemon ruby.