Dear smartmundu,
Unfortunately, there is not way to "seal admission" to any MBA program--no matter what your profile looks like. To give yourself the best chance for admission to a top 20 MBA program, you will want to score in the 700s on the GMAT as your profile (engineer from India) is over-represented. Likewise, you will need to use your essays, interview and recommendations to distinguish yourself from the many other similar applicants and make a compelling case for your admission. You have some interesting work experience that is a little different from the IT consultants and programmers--use that to your advantage in your application. Finally, I encourage you to identify a broad mix of schools to apply to as that is the best way to ensure you will be in business school in fall 2011. Look beyond the usual names and top of the rankings--explore the plethora of possibilities as many programs offer top quality in their curricula and resources, but do not receive the same recognition.
Good luck,
Lisa