The COPR and IM-1 visa is only valid for a single entry. If you have already landed, you won't be able to get on an airplane with a COPR.
Like I said above: if you're currently in Canada, and you send your passport away, you do not "land" unless you attend a visa office or you flagpole. If this describes you, when you get your passport back, do not leave Canada until you go to India. Then you can return with the COPR and "land" at that time provided your COPR has not expired.
If you land by interview or by flagpoling, you need a PR travel document to get on an airplane to come back to Canada. You cannot get one in Canada. You must apply in India. I have no idea how long it takes.