you can get suicune in Pokemon leafgreen and firered if you starter Pokemon was a charmander. after you finish the game, you will randomly encounter it in the tall grass. good luck.
In Gold/Silver, it will be roaming Johto.
In Crystal, it will be in the Bell Tower.
In Firered/Leafgreen you have to have started with Charmander and beaten the elite four then it will be roaming Kanto.
In Colosseum, a shadow version will be in the Under Subway.
In HeartGold/SoulSilver it can be encountered on Route 25 and the Burned Tower.
For all the other games, you can only acquire it through transfer or trade.
you cant you have to trade
Do a celebratory dance.
There is no most common place to find Suicune (sometimes misspelled as suicun) in Pokémon FireRed. Where it goes is totally random.
it all depens on the starter charmander=suicun bulbasuar=enti squirtal=rikou
To acquire a Suicune, you must have started with Charmander. The legendary dogs will appear corresponding to what Pokemon you started with. For example: Raikou-Squirtle Entei-Bulbasaur Suicune-Charmander It will appear in a random route in Kanto, and only after you have beaten the Elite 4.
Moltres articuno zapdos raikou entei suicun rayquaza groudon kyogre ho oh and lugia and mewto and palkia dialga giratina and last but not least powerful legendary of all arceusgroudon
Suicune you get at north cave in snow soft city when the tide is low. Mesprit you get in thin forest south of selaro town. Latios roams Gento, you randomly find him in grass.
ho-oh, lugia, (On covers) Entei, suicun, and, Raikou. Any others will have to be traded over by red, blue, or yellow, Green if in japan. :) you can actually got certain legendary ln gold that you can get in ruby so if you migrate from Sapphire you can have two water guys or Kyogers
First weaken Suicune to 1 HP using mainly False Swipe which can be found in a department store such as the one in Goldenrod City or using a weak electric attack then use several Ultraballs if all else fails make sure you save the game before you battle Suicune so you can keep trying. I caught ho-oh with a Masterball so I had to try using an Ultraball to catch Suicune and I succeeded and am happily training my new Suicune.
First, take a visit at Burned Tower in Ecruteak City. Then Suicune, Entei and Raikou will run away. Entei and Raikou will usually found at route 37 but if you battle, it will runs away. If you use some moves that prevent it from flees, it may uses Roar. About suicune, you won't be able to battle it until you go to kanto region. Suicune may appears in many places so you will have to find it. I remember it appears at Burned Tower, then The place of Chuck's gym leader city. Then in the front of Mt. Mortar, the route when you reach Kanto region, Cinculean city's bridge, route 14 and final route 25 is the place you can battle and capture it.
there is almost nothing else to do but if you have not gottin any of the legendary dogs than you should.if you caught mewto with masterball than good luck trying to catch the legendary dog.best way to catch dog is by using repel and going to different routes trying to find the pokemon.(squirtle enti= charmander = suicun bulbasaur = rioko.continue on with your qwest to become a Pokemon master.