From what I’ve heard offers can go till June. However offers in June might vary on how many people reject a spot in RMC. It’s inconvenient because most other universities want a definite answer from you by June 1st.
For me the recruitment center actually photo copied it and gave it back. Then I got email from RMC to send them it too. Email to RMC also had additional papers too that I had to fill. This was however in Ontario and I’m not aware of how the process works for other provinces.