Hey Nalanda,

It is not possible to study  medical in USA directly after 12th .Minimum qualification for medical in USA is Basic Sciences i.e equivalent Bachelor's degree in India.After completing Basic Sciences on ehas to take MCAT-medical admission entrance test. Students clearing MCAT ,get an entry to medical schools in USA.Also there is no MBBS course in USA .The medical course there is MD degree.

You have these options if you want to pursue medical in USA after 12th:

•  12th from India ->Basic Sciences (3/4 yrs)from USA ->MCAT-> MD in USA->USMLE ->Practice jn USA
• 12th from India->Bachelor's 3 yrs from India->MCAT->MD from USA ->USME-> Practice in USA
• 12th from India -> MD (5 yrs from Central America or Caribbean)-> USME ->Practice in USA

Hope this helps!!