Get all pokemon in your pokedex. Then talk to professor burch (or h/e you spell his name)
and he will give you the three jhoto starters, hope this helps =)

~lilcrazy

just fill your entire sinnoh pokedex then talk to professor rowan and go to route 221
after talking with professor oak aswell and when you get there, there´s a park there,
enter and talk to the guy inside in front of the black door, save your game and enter your
pokemon ruby/saphire/emerald in your ds advance slot and when you initiate your game you
should see an option that says migrate from ruby/saphire or emerald select it and choose
the pkmn
just one thing its a one way transfer only