you should come to montreal as soon as possible in three months after your landing if you hope to become a resident of quebec,otherwise,you have to wait for a year.
what you should do is to rent a house which you could sign a lease to prove you move into montreal in three months.that is all.so easy.
if you cant not move in in time,so long as you can get a lease from anywhere to prove you already live in montreal,you are also a resident of quebec.