I am a bit confused by your posts here. I am not sure if you have been able to define your question correctly in this case.
RVR depends on what type of approach, visual, Non Precision, Cat 1, Cat 2, Cat 3 A, B and C.
On your approach plate it is normally always given in RVR.
If RVR less than 1500m, than this will be reported in the METAR, not the TAF.
If no RVR in the METAR, than that means the RVR is over 1500 m.
You will use your TAF for planning purpose, but to know if you are legal, you will have to convert it to RVR. This figure decides of how you plan your alternates.
Also the type of approach you are planning what the criteria will be for your alternate.
Example your approach is CAT II/III, your planning minima must be for CAT I RVR, for a Non Precision, planning minima are Non Precision RVR + 1000 m, MDH + 200ft
If you are not given a RVR, you use CMV for planning purpose.
Cat. A, B, C and D aircraft will have different RVR criteria depending what kind of approach your are talking about!
As far as I can recall CMV can not be used for Take off planning, but will need to revise to confirm this.
In addition for Non Precision approach you also need to take into account the cloud ceiling for planning, must be at or above MDH.