Guys, the RTM is usually the last version before the final release.
Well that isn't totally correct the RTM 'is the final version', not the last version before the final release - in the old hard copy world that is what was sent to manufacturing be turned into CDs.
Well, nevertheless it's the way Avast does it.
Regardless of how they do it, build 2015.10.2.2213 still isn't available through the avastUI Program Update on 2015.10.0.2208 which is why there is so much confusion in calling this
RTM Update - AVAST 2015 R2 RC2.
As has been mentioned RTM and R2 RC2 shouldn't be used in the same context.
One or other of the two terms should be removed.