In the postgraduate exam, it is generally more appropriate to send your resume to your tutor after the exam results come out.

You can email the teacher to introduce yourself before the exam. It is best to send a resume to the teacher after the exam results come out and see the teacher before the interview. Of course, if you especially want to talk to this tutor, you can go directly to the tutor for an interview in advance, read more papers and research fields published by this teacher before the interview, and get to know the laboratory with his brothers and sisters in the laboratory.