There isn't a rayquaza orb, but I'll show how to get both Pokemon.
Groudon-Beat the game and beat Red in Kanto. You need all badges to go to the mountain with both Red and Moltres. Also you MUST get a starter Pokemon from proffessor Oak in Kanto. Next you go to proffessor Elm and talk to him. He will give you the (Jade?) orb and you must go to the route next to the Pokemon (Reserve?) Go across the water and you will find a cave after you rock climb. Go in it and you will find groudon.
Rayquaza-You need both kyrogue and Groudon in your party and bring them to the same cave used for Groudon and rayquaza will appear.
Kyrogue- Trade from a different game. (Found in HG following the same steps for Groudon)