After MBBS, what are my Options in USA?

You must get permission to take the USMLE.  This is done through the Educational Commission for Foreign Medical Graduates  they will vet your credentials to make sure you are adequately trained and can speak English.   They then issue permission to take the USMLE.  Then you generally must get letters of recommendation from the US….which means volunteering or working not as a physician.  You may have to return to your home country.  Then there is the Match.  The US graduates about 50 fewer doctors than there are residencies.  Getting a spot is extremely difficult and if you get one it will be in family practice, pediatrics, or internal medicine (generally).  These residencies are generally not the best in the field.

There used to be the 5th pathway where FMG’s did essentially another year of training, but that was phased out.