Thanx for correcting me St.
The thing is that once your applicaton is approved the Canadian immigration authorities give you a visa to go to Canada.Once you go to Canada you then get your Canadian Green Card.If for some reason you do not go and your medical expires you hav to start the whole process again.But I believe that once you get your GC you must then spend atleast three years out of the next five years living in Canada.So it seems that you can technically still live in India for another two years after getting your Green Card.This is what a friend who recently migrated told me but I havent found it written anywhere.If some one could please verify.