How far into Pokemon Firered/Leafgreen or Emerald do you have to play before you can migrate Pokemon from it?

beat the game on peral or diamond and complete the national dex go to talk to the professer and then the old professor will come and talk to you then go to the city where the professor is and go down until the water then surf down until you need to turn to the right you will be at pal park talk to the guy inside he will ask you to choose six pokemon save then turn off your ds turn it back on and click migrate from blablabla then choose six pokemon then say ok then play pearl or diamond go inside the place where you catch the pokemon then waalk in the grass and you will find them. you dont need to beat the other games i think.

the only requirement is that you need to have at least 6 pokemon in your PC box. That's all. I got all the Kanto starters and a pikachu over the course of a few days (since you can only migrate once a day) easily. I just caught a bunch of pidgeys and rattas and threw them in the box with like bulbasaur and migrated

u need to beat the elite 4 in fire red and the others and thenbeat the elite 4 in pearl or diamond then u can ( u can only migrate every 24 hrs and u cant change the time clock i tried :( doesn't work )

u can also use the pokemon box.

it will allow u to move them from one game to another. as long as u have 1 pokemon left in the game.