You can't. Use Action Replay.
you cant catch a deoxys in Pokemon soulsilver or heartgold but u cud trade it over from ruby Sapphire or emerald or use an action replay
its on birth island
You cant get it but if you have GBA games of Emerald and catch it, then Send it to HG/SS in Kanto ( you can go there by boat in the place where the light house is
you cant without hacking
there are two ways of getting deoyxs 1:find the Auorora Ticket and go to birth island. 2: trade it from another gba
its not an emerald its RAYQUAZA the main legendary Pokemon in Pokemon emerald.
You cannot get a Yanma in Pokemon Emerald, as only Hoenn Region Pokemon can be found in Pokemon Emerald.
Sinnoh Pokemon DO NOT EXIST IN EMERALD!!!
emerald no doubt
There is no PalPark in Pokemon Emerald.
where can i find groudan in Pokemon emerald