RTCP is the control of the programmed tooltip in relationship to the part's origin, even when rotational planes come into play and are moving at the same time.
This is method should only be considered if the machine and control has this option enabled
A basic 5-axis machine without this function would need the work origin placed at the pivotting point, and the stock/part placed in respect of that pivot point and then programmed. Any repeat of that part has to be setup identically or the program will fail.
This RTCP method allows you to place the work origin, either on a part/stock or fixture, anywhere in space and the point the tool has to move to is calculated continuously from it's current position back to a continuously moving "fixed" origin - this is the hard bit to understand about TPC (Tool Point Control).
In Mastercam, you program to suit the machine capability, the post may need customizing to utilise this function and output additional code.
To program for RTCP, you only need to place the part and stock in relation to a WCS origin for that setup, and that WCS wil need to be used for all operations for that setup, the post should take care of everything else ( this, by the way, is a standard mastercam programming method - with or without RTCP )
Without RTCP you can only do 3+1 or 3+2 programming, you cannot use 5-axis paths---uless you have the origin at the pivoting point of the machine.
The more accurate that this pivot point is set, for any method, the better blends you have, and a more accurate part will be created,---it'll look good too.