I have 8 years of IT experience in India, I want to do a Master of Science in the US. Would my already long professional experience hurt my chances to find a job after the MSc? I intend to settle in the US instead of coming back to India.
I would expect that it almost certainly does not hurt your chances. Many people proceed their academic education or career after professional experience. In our Master programme, this is treated as a significant plus, and I would be very surprised if companies wouldn't do the same.
But for the non-academic portion of the question (I infer you mean a job outside academia), you might want to ask at The Workplace and get opinions there.
You will be a very strong candidate in US provided you go to at least a reputable public university.