If you do not get into ROTP then you can apply as a Direct Entry Officer (DEO) once you graduate from an accredited university with an undergraduate degree in nursing and having attained your RN license in one province.
The number they take for ROTP varies from year-to-year. I would say between 6-12 but the CFRC will have the latest numbers.
It is important to remember the selection criteria is quite different for the ROTP versus DEO. In the ROTP the CFRC is generally looking for academically bright high school students who will do well at university and thrive in the academic environment, have leadership potential / experience, as well as all of the other qualities they look for in officer candidates. For DEO they are looking for someone who has the correct credentials (degree, license, etc, etc), but also, ideally, who has training and experience relevant to the occupation, as well as leadership potential / experience, as well as all of the other qualities they look for in officer candidates.
For example (although slightly, but not totally, exaggerated):
ROTP is competitive because you are fighting against that nerd in high school who has a 98% average, got into 3 nursing programs unconditionally in the first round, is the high school president and captain of the field hockey team.
DEO is competitive because you are fighting against that person who graduated near the top of their class in university, was the nursing society president while in school, is now working in a busy ER patching people up, has multiple short medical courses (ACLS, TNCC, ITLS, ABLS, etc), volunteers with the girl guides on Thursday nights, and runs marathons in there spare time.
Applying is free, you will never know unless you take the plunge.