Timer balls are only in Pearl and Diamond
you can only get timer balls on rustboro city pokemart on emerald
Level balls are only available in Gold, Silver, Crystal, Heartgold, and Soulsilver.
A timer ball is good to use when you want to catch a Pokemon you've battled for a while. The more turns you have in a battle, the better more chance you have to catch to Pokemon with a timer ball. (I caught my Groudon in Emerald with a timer ball ^_^)
I find dusk balls much more helpful.
There are 2 ways to find them: you can go to either pokemart or you can go to solaceon town[the man who lives beside the pokemon center. He will tell you what pokemon he wants,but don't worry,he will not take it. Once you gave him the pokemon he wants, he will give you 3 dusk balls, timer balls, etc.
Stock up on ultra balls, heavy balls, dusk ball, timer balls...basically whatever pokeballs you can find. I caught mine with an heavy ball made with a black apricorn by kurt. Pokemon heart gold.
You need an AR then go to codejunkes.com tipe in Pokemon heart gold or soul silver then find the code for 999all pokeballs
Lower its HP until it's at the Red marker. Find it again, then put it to sleep with a fast Pokemon. (Suggest darkrai) Get a variety of poke balls and throw them at the Pokemon to try and catch it. If you have used poke balls a lot of turns then throw a TIMER BALL.
You can't find registeel in Pokemon HeartGold.
You can find it in Pokemon Platinum, Pokemon Crystal, Pokemon HeartGold, and Pokemon SoulSilver.
unkowns {pokemon}
You cannot find Latios in Pokemon HeartGold unless you went on wi-fi and got the Enigma Stone