Hi Rajiraji,
You can research each School's class 'demographics' to get a sense of what makes up a 'typical' incoming class. With what you've described, you might end up being 'older than average' in terms of age, but you'll have an interesting background, which will help you to stand out (and THAT is a good thing).
Since you brought up Stanford, you have to understand that you're talking about one of the most competitive Schools in the US, so your overall profile has to be strong AND you have to present yourself correctly. It might also come to pass that you end up doing everything perfectly, but you don't get in....because that's how 'the math' works sometimes.
The answer to your immediate question though is "NO", your age will NOT be a problem.
GMAT assassins aren't born, they're made,
Rich