Hello,
If you are considering only the top-tier B-Schools, then I must say that a score of 610 will not be sufficient with 2 years of work experience. I don't want to disappoint you; I am only trying to help you with all the practical info that I have.
A B-school application is not limited to a good GMAT score. There are other aspects as well like your application essays, quality of work experience, your involvement in extra curricular activities/social service etc. For example, you have a lil over 2 yrs of work experience, but if that is in your own company that you have founded, that would do wonders to your application packet!
You can re-take the GMAT. But you must be prepared to bear the extra costs of re-taking the exam. If you re-take the test, all your scores in the past 5 years will be reported to the schools that you indicate as 'score recipients'.
My advice to you will be: Send your applications to the schools of your choice within the 1st application deadline. Since admissions happnen on a rolling basis, that will give you a better chance. And work on the other aspects of your application.
Hope this info was of help to you. Furthermore, I am coming up with a web portal which will help MBA aspirants like you to be better informed and be equipped with all the relevant info so that they can make it to their dream B-Schools. For that I am conducting a small survey which takes just 2 mins to complete. Can you please go to the following link and take the survey? This will help me design the portal for the benefit of fellow MBA aspirants.
Many thanks for your assistance.
Cheers
http://www.surveymonkey.com/s.aspx?sm=8X_2bvSx2_2b1RJJ7aXaUz5HEA_3d_3d