They didn't mentioned whether we should pay for one semester or the entire year. I'll copy some parts of the offer:
This offer is conditional upon the receipt of an official transcript confirming that your previous degree has been conferred . Upon your arrival at the University, you will be required to submit official transcripts and official translations for all institutions you have previously attended. Your condition must be cleared by submitting the required official documents to your department by September 30th, 2019. Failing to meet these conditions, this offer will be rescinded.
Currently the 2018/19 academic year McMaster University Regular Graduate Student Tuition Fees for Visa students for one year (September to August) are $17,096.22 plus supplemental fees of $997.06. Fees for the 2019/20 academic year have yet to be determined and are subject to change.