Although Indian students can become a doctor through either route, they need to understand the advantages and disadvantages of each route.
Most US medical schools require that a student be a US resident or permanent resident. If you are a US resident then medical school in the US may be an option. However, for most Indian students, the limited number of US medical schools that will accept international students means that you will have limited opportunities to gain admission to US medical schools.
This limitation on foreign medical students is also true for the BS/MD programs and there are only a handful that will consider international students.
Because Indian students can attend medical school in India right out of high school this is an attractive option. It is not only a quicker but a much cheaper option than US medical schools. However, coming to the US for a residency program or getting a position in the US after residency is much more difficult for those students who did not do their training in the US.
The decision of what approach to take is somewhat more complicated for those Indian students that have US citizenship. Attending a BS/MD program or getting to US medical school through the traditional route will cost more than medical school in India. However, you will be in a much stronger position for getting a residency and a job practicing medicine in the US by attending college in the US.
Each family needs to weigh the additional cost of US medical school compared to the potential long term gains by being a physician in the US.