GRE x GMAT

Which test would be better for someone wanting to pursue a master in the Marketing area?

I read that the GMAT is accepted in more business schools when compared to the GRE test and that the GMAT is mostly used for pursuers of MBA degree, I plan to take an MBA in the future so if I take the GMAT to be accepted into a Master program will it be possible to retake the test in the future to use for an MBA program?

The GMAT is preferred for most business programs. If you take the GMAT, your score is good for 5 years. If you do not go back for your MBA within those 5 years, then you would need to take the GMAT again. So yes, it is possible to take it for masters admissions, then take it again years later if you choose to return for an MBA. You can also retake the GMAT within 5 years if you are not satisfied with your score. It need not be a once-and-done thing.