I'm not 100% sure I understand your question.
I'm assuming that IMS = International Medical Student. The usual abbreviation is IMG = International Medical Graduate.
Assuming I got that right, you're looking at next year's match (2009).
You should have Step 1 and both parts of Step 2 completed and reported prior to Nov 1, 2008, earlier is even better. If you are interested in / need an H visa, then you will also need Step 3, which should be completed in the same timeframe. Given how much time there is between now and then, you shouldn't have much trouble (although remember that Step 2 CS and I think Step 3 are only offered in the US and will require travel)
Good luck!