You get Jirachi, Mew, and Deoxys from pokemon events.

U can get the Regis by betting a wailord and a relicanth and put wailord 1st and relicanth
last then go to pacifilog and surf west keep surfing til u get 2 a spot wif lots of rock
round it then dive. once ur back on land underwater, go to the very back and use dig. the
an earthquake will happen and u can find the regis around in caves.

I forgot to put down Regirock!!! :0

go to serebii.net click on emerald under video games its very helpful go to the right
click on faraway island, birth island, navel rock and the regi way