Its amazing money for someone living in India, but the guy in question was moving to America. If he's good enough for them to want him to work in the U.S., they should be willing to pay him appropriately to do so.
I switched from the helpdesk at my first job to being a senior sysadmin working with the highest paid people on site for my gig. My company wanted to give me ~2% raises a year from the helpdesk wage to what was the average for my new position, vs. bumping me up to the avg salary for the new position when I switched teams.
So I would have worked side by site with my peers for ~10 years to catch up to what I should have been paid walking in the door. Since they wouldn't pay me what I should have been worth I quit.
Ask yourself if say worker from the south say moved to a California and a company policy paid blacks less than whites - the courts woudl crucify them
The policy more likely is: We pay X dollars for position Y in the USA, and less than X dollars for position Y in India per company policy. There isn't anything illegal about that. Also there isn't anything illegal about not bumping up his salary if he moved from India to the USA (even though I don't agree with this).
Interestingly, the US Supreme Court ruled Asian Indians to be Caucasian, probably white, but not really white. Pretty tragicomic stuff, the old race based citizenship requirements.
I'll definitely be looking for something better, but until I find it I don't really have any good options. I'm sure someone trying to leave India is in a similar situation.