Received offer for Law at Oxford, can I switch to Law with Law Studies in Europe?Watch
I expect your best bet is to ask your college before results day, but others with more Oxford experience may say otherwise...
We did a transfer for a student last year: he/she applied to transfer after starting the course, the Law School agreed but set a minimum level of attainment in the first year Law exams (these are called 'Mods' and take place after the first two Terms). The student met this target and transferred.
Our advice would be to talk to your college after you arrive in Oxford since, as stated above, the Law School as well as the college need to agree to a transfer.