Hey Ram,
I have almost identical background as yours. I also have my own startup(I contribute on a part-time basis). I am 32 and going through the ordeal this year. All dings in the first round. I have slight hopes on the second round outcome. I have a GMAT score of 700 and did a decent job with essays. But so far, no luck.
Some unsolicited advice :
1. It's going to be very tough. Manage your expectations. Someone once told me that getting into a top US business school is a two year process for Indians.
2. Get a stellar GMAT score. I think a lot of people underplay the role of GMAT in the admissions. A very high GMAT will probably make the adcom take an another look at your essays,
3. Write stellar essays(this is going to take the maximum amount of time).
4. Why MBA story has to be perfect. Career goals should be crystal clear and make sense. By looking at the resume and essays, the adcom should know why you want an MBA and how you will flourish with it.
5. Play the round strategy properly.
I know all of these things in the hindsight. This sounds easy to execute, but it's a lot of hard work. One idea is to look at 1 years programs in Europe. They are relatively easy to get into and age is not going be a major issue there.
First step for you is to understand why you need an MBA clearly(not just getting senior management position). Start looking at the linked profiles and get a clear understanding of your career trajectory post-MBA. Explore post-MBA careers paths. Talk to current students and alumni.
If you are committed and strong, I don't see any reason why you won't make it just because you are 33. But the path is difficult and at the end of it you will come out as a better person. All the best!
Thanks,
Prodizy