You will need to check whether you need to apply for a visa as a Student Visitor to come to Oxford for this course. Some nationalities must apply for a visa before travelling, using the course confirmation of place letter provided, others can show this letter on arrival to be stamped in as a Student Visitor. Check on the Home Office website whether you will need to apply for a visa: https://www.gov.uk/check-uk-visa
For further information on applying for a visa or entering the UK as a Student Visitor, see http://www.ox.ac.uk/students/visa/before/visitors
If you require additional documentation to support your visa application, please let the course administrator know at least one month before the date of travel