If you are within a short enough time of the end of your studies when your application under SMC is being processed that you could realistically be applying for skilled jobs and accept an offer to start quite soon, then you can apply for Residence. If someone applies when they still have a large part of their course to go, then INZ will refuse residence under SMC, because the whole basis of this route is that the person is supposed to be ready to be employed in a skilled job, to contribute to the NZ economy.