If you study from Private colleges ,you will not get any work permit.I believe you have to get in IELTS (with overall 6.5 band ) for seeking admission in Govt college.
You will not get any work permit from a private college/university. Your 1 year business course will not be considered for the duration of your PGWP. You must be attending full time classes in a public school in order to be eligible. If you are changing schools you can update the DLI number online through the mycic account