Your chances don't hinge on your GMAT score given where it's at now.
For HBS, your chances are slim to none. A 30+ engineer isn't what they're looking for. It's not about being Indian or "not" IT. It's that you have the double whammy of being too old in a crowded occupational category that they don't particularly favor (engineers) as much as they do those who worked in financial services or management consulting. And yes, in terms of class composition it doesn't help that you're an Indian engineer (even if it's not IT). To their eyes, a different shade of engineer is still an engineer.
However, don't let me stop you from applying. If you want to go, by all means apply, just keep your expectations realistic about what your chances are. If you get in, great - consider yourself extremely lucky.
And focus on the EMBA programs. They are likely to be a far better fit than HBS anyhow (you'll be in a class with a bunch of kids and you will feel old).
Alex Chu
alex@mbaapply.com
www.mbaapply.com
http://mbaapply.blogspot.com