I have applied for a visa in canada. During this processing time I am planning to apply for some jobs, how will I mention it in the cover letter?

Jobs in Canada? You just say whatever you would open it with and then say my visa type whatever is currently processing, I plan to arrive (ballpark when you think you will arrive) , and leave it at that.

Don’t mention it in the cover letter, but add to the bottom of your CV.

Canadian Visa – Pending (expected x/2015)

Welcome to Fluther.

Never having applied for a visa to work in Canada, and having only a vague and casual understanding of the process, my belief is that the Provinces each manage their own visa applications. That is, you would apply to the Province of Quebec to work in Quebec. So there’s that. In addition, according to the instructions (now that I have looked them up), the visa is also employer-specific. So if they don’t already have you on their radar, then it would seem to me that the résumé would be pretty much useless, anyway, wouldn’t it?