I think the key point is the working experience and the potential you have already acquired.
Say if u have been working for 10years, and now you quit the job and fully devoted to GMAT preparation for 6months, I am sure that the admission committee will neglect such a period.
But if you have only worked for 2years without outstanding achievement, a 6months of jobless situation will probably be a negative factor to the committee.
Anyway, wish you good luck! | 
