You can appear for USMLE or United States Medical Licensing Examination in order to do medical pg courses from USA. It's same as All India PG Entrance exam where you study up all your MBBS Subjects and write the exam. USMLE is a three step process where you have to score a very high percentage. Based on your marks you will be given a stream to get your MD in. USMLE 1 and 2 can be given in India after getting an appointment but for Step 3 you have to go USA and sit for interview. You can check the detailed eligibility criteria here-

https://studyabroad.careers360.com/articles/usmle-eligibility-criteria