You could wait for your PR card to be ready for pick up because then they will send you a letter and tell you where to pick it up. If you really want to know now, you could try the call centre and ask or look at this list:
http://www.cic.gc.ca/english/information/offices/help.asp#on and check if any one of them seems close to you. You could then go there and ask them in person if they are really your office or if they know which office you should go to.
Immigration Forum
