How Do I Catch Rayquaza In Diamond Without The Action Replay?

You have to talk to the 2 people at the battle tower out the front then go 2 the turnback cave (where you find giratina) when you get in you keep going forward till you can't then left 12 rooms then down 4 then you need in your party your starter level 76, all 4 regis all level 94 (regiice,regirock,registeel and regigigas) and one of eevees evolutions level 68 then battle him

he is level 60 and extremely hard

You can't unless you TRANSPORT IT from emerald

You can't but you could get it from pokemon emerald and trade it