TRV, also referred to as a visitor visa or Canada Tourist visa, is an official document issued by a Canadian visa office that is placed in your passport to show that you have met the requirements for admission to Canada as a temporary resident (either as a visitor, a student, or a worker).
There Are A Number For Basic Requirements For A Canadian Visitor Visa:
Visitors are allowed a six month stay from the day they entered Canada. If the officer authorizes a stay of less than six months, they will indicate in your passport the date by which you must leave Canada. If you want to stay longer than your authorized stay, you should apply for an extension at least 30 days before the authorized end of your stay.