May I assume you are inquiring whether or not you can practice medicine after completing 1 year of a medicine residency and passing Step 3?
Technically, yes. There is no current requirement that you complete ANY residency to practice medicine, only that you have an unrestricted license (which you can apply for after passing Step 3).
HOWEVER, just try and find a hospital or practice that will hire you. Without completion of a residency, you are not Board Eligible and you will find that many insurance companies and MediCare will not reimburse you for your services.
You can do some Locum Tenens and 'Doc in the Box" type of work, but this generally is not suited for long term occupation. There is also the option of having a "cash only" type of private practice, but with the increasing savvy of the medical care consumer, it is unlikely that you will find many paying customers once they find out you haven't completed a residency and are not BE/BC. Besides, many patients cannot afford medical care without insurance, and you might be limited to "cosmetic" or non-insurable procedures.
What is the real question you're asking? Are you so unhappy with your program that you would consider quitting and not trying to find another residency? Do you dislike IM and wish you had chosen another field? Or are there personal reasons why you feel you cannot complete your residency? If you really wish to practice medicine, you would be foolish IMHO to not complete a residency - if not the one you're in, then some other one.