You need to have defeated Misty before you get Suicune
to find suicune go to curelean city towards route 25. it'll be standing there waiting. Entei, Raikou. Roam around
Olivine town, Outside Mt motar, Vermillion city then Cerulean cape
i would think it be the same as the original silver and gold and that would be to the left or straight down from were the tower is
Check theses places: the burned tower, Cyanwood City, Mt. Mortar, Vermillion City, Route 18.
you need to see it in these places: burned tower cianwood city north route 42 ss aqua port vermillion route 15 cerulean cape (battle)
Suicune is a hard Pokemon to catch Suicune will move around diffrent places. You normally catch Sucune at level 40 use your map to try and find Suicune on your pokegear. It is hard but you will get there
If you can't find Suicune, then that either means you never visited the Burnt Tower in Ecruteak City or you haven't arrive at the Kanto region yet. To find Suicune, you'll need to first go to Ecruteak City and go inside the Burnt Tower. Go to the basement of the tower and you'll see Suicune, Entei, and Raikou. As soon as you see them, though, they will all run off, except for Suicune who will look at you before running away. After that, you'll have to chase Suicune at various places in the game before finally seeing it outside of Bill's House on Route 25, after Misty returned to her gym.
You have to follow Suicune to all of the places he visits. In the Johto Region, he'll be in the Burnt tower and at the top of Cianwood City. In the Kanto region, he'll be on Silence Bridge, and end up at Cerulean Cape, where he'll finally battle you.
Well you don't literally catch it in one place very soon . It runs around in the johto/kanto region. You have to catch it while it is standing in places where it's even visible out of battle. Then you can go to route 25/26 and meet it there and battle. For more info/example search" how to catch Suicune in pokemon heartgold/soulsilver"
Suicune is probably not on route 25 if you met him everywhere else because you haven't caught Entei and Raikou. If you caught them and Suicune still isn't there then look at the places Suicune was, then go back to route 25 WITH ENTIE AND RAIKU IN YOUR PARTY!
you go chasing after it with the guy that saw the whole suicune thing (he does not follow you). later on he gives you the hint that suicune likes hilly, watery places up north.
suicune travels to Clainwood city then Route42,then goes to the Kanto reigon.You can capture it after you defeat the elite four and campion