Via cic website :
If my immigration application is refused, do I have to wait before I apply again?
If we refuse your application to come to Canada, you can apply again at any time, unless your decision letter says you can’t. You should only apply again if you can include information that you didn’t include before.
If you had legal status and lost it (for example, if your work permit expired and you did not renew it in time), you have a small amount of time to re-apply. See your decision letter for details.
If my immigration application is refused, do I have to wait before I apply again?
If we refuse your application to come to Canada, you can apply again at any time, unless your decision letter says you can’t. You should only apply again if you can include information that you didn’t include before.
If you had legal status and lost it (for example, if your work permit expired and you did not renew it in time), you have a small amount of time to re-apply. See your decision letter for details.