A literal metric ton of Americans is about 12 individuals. A short ton is about 11.
I presume that a figurative "ton of Americans" would be many more than that, because it seems like American enrollment in India's medical schools should be more than just 12.
The bars in Bangalore are filled with medical students. There are always a handful of Americans studying with them. I have a few friends who graduated recently and are now back in America doing their residency.
Go check the numbers on how many over seas medical students come back state side and actually end up as medical doctors. Passing the board exam and getting into residency programs is a lot harder these days, since most programs are aware that this is happening.