You have a good GMAT score, but your undergrad GPA is on the lower side. Competition is stiff for candidates from your background[Indian/IT/Male]. Your high school marks are good but your secondary education marks are again low. There is a clear lack of consistency in your performance. I think your GMAT score might be able to make up for all this.
You have not written enough regarding your work experience. It is not the position that you hold matters rather the quality of your work-exp is important. Did you have a lot of leadership experience? Were you felicitated with awards from your employers?
You can certainly write about your freelancing experience in the application essays. You can expect a lot of questions on this. B-schools generally want to understand the candidate's story, why he made various choices in life and where he is heading.
How is your digital advertising start-up going? Have you worked out a plan about who will be running the business when are out pursuing MBA?
Your extracurricular activities seems to be really good. You may be able to fill holes in other aspects your application with this one. Do stress more on this part in your essays.
You may apply to ISB, Haas, Boston, Oxford and
McCombs. If I were you I would not apply to more than five schools. I would suggest you to focus all your energies on writing excellent application essays. You may even have good chance at some of the stretch schools. Good luck!www.InterviewBay.com