The minimums (give or take a few feet) I know for anything from 737 upwards...:
CAT 1 200 DH - 550m RVR , manual landing
CAT 2 100 DH - 350m TVR , manual/autoland(on most)
CAT 3a 50 DH - 200m RVR , autoland
CAT 3b 20 DH - 125m RVR , dual channel autoland
for take-off: min 125-150m RVR depending on aircraft
A visibility of 100m is below everything - for good reasons.
Attempting it without a flight-director sounds rather dangerous/foolish to me.
The visibilty/RVR is far more important than the ceiling.