The Social Insurance Number (SIN) is a nine-digit number used in the administration of various Canadian government programs. You will require a SIN to work in Canada or to receive government benefits. Apply in person at a Service Canada Centre.
When you apply, you must have your original documents with you:
Work Permit (issued by Citizenship and Immigration Canada)
Study Permit (issued by Citizenship and Immigration Canada) AND a contract of employment (job offer letter signed by both parties) from the learning institution or from an employer on campus.