is it necessary to complete full course to get migration certificate if I want to leave any college and want to join another college
If your are currently studying in college and want to leave to join any other better college or due to any unavoidable reasons then you have the full right to leave the college and then join the college of your preference.
For this you just need to put a college withdrawal application in the administrative office of the college concerned. They will accept your application and will then provide to you your required documents like migration certificate and others. And to your question I would say thet you need not to complete the entire course.
Moreover you can contact your college helpdesk to know the procedure for putting college withdrawal application to leave the college in between the course
Hope it helps you.