If you land in Canada, you can move to Quebec anytime you want. However, to become Quebec resident (i.e. enjoying the reduced tuition fees, etc), you have to live in Quebec continuously for at least 12 months, and you cannot be in Quebec solely for the reason of studying. However, if you were born in Quebec, you are considered as a Quebec resident the day you move back to Quebec. This does not apply to Canadian citizens born in other provinces.