WHEN AND WHERE TO APPLY !?

Hello,
Greetings !
I am Ninad from Ahmedabad . I am currently persuing my BBA from Gujarat Univ.( 2nd year 5th sem) and i am planning to do my masters in Marketing from abroad.
I am currently working with a US based real estate as sales executive and have worked in Hyundai before in corporate sales.
Now the questions that i have are-
1) which is the best country to do my masters from USA,Canada or Singapore ?
2) what is the eligibility criteria for that country ?
3) With GMat is Work experience required !?
4) when should i apply !?

Please revert back to asap in but confusion and chaos.

Regards,
Ninad chitale
chitaleninad5@gmail.com