There is no word from any Canadian carrier yet on when or if the S6 Active will be available. Samsung Canada also does NOT have the device even listed as being in Canada either. I suspect once Samsung releases it fully in Canada, then the carriers will be able to offer them to customers.
First start with Samsung.ca. If it's not listed there, it's not in Canada yet. Once it's on their website, then one of the Canadian carriers will likely be getting it. Considering Samsung is having really poor sales right now, I can't see them bringing another model to market, especially a niche model.