You can always get another Suicune in a trade, then trade it back, then it's PokeDex data will show up and you can track it.
But don't got huntin' for it yet, if you don't have MasterBalls, then go into tha Cerulean Cave and catch a Wobuffet with tha ability Shadow Tag, this prevents Suicune from escapin'. This is exactly how I did it, the Wobuffet was around level 55-60ish. But it's hard, it WILL take multiple tries, just don't kill it cause it will never return, and if you damage it and it flees by destroyin' yer Wobuffet, tha next time you encounter it, it will ahve the same amount of health as it had when you last left off.
Hope I helped...
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