I believe for dubai visa office is UAE below is the link
http://www.canadainternational.gc.ca/uae-eau/visas/index.aspx?lang=eng&menu_id=4
"We provide these services to residents, nationals, or persons legally admitted to the United Arab Emirates, Bahrain, Kuwait, Oman, Qatar, Saudi Arabia* and Yemen."
so i am guessing u will need proof that u r legally in UAE.
if u can apply from india better not because u get jo here but bec in india it process in 2-3 weeks while in uae it takes 2 months. regarding the Ban.. its a labour ban.... that is for anyone who leave job for any reason.... but this ban stop u for working not entering uae... u can still enter uae on visit but can not work..... do not mix visa with job.... u ca n apply frm anywhere in the world.. u have to be leagaly admit to the country of residence where u applying frm other then ur home country.... go for ur job... and aply visa from dubai.. no issues