Can I use the autoland mode if the airport is unknown to the FMC database? Can I use the autoland if I have to land on an airport which is not known to my FMC database? Is it possible to insert the coordinates to get the autoland mode?
Autoland is an autopilot mode.
AUTOLAND could be « armed » while the autopilot is receiving FMS inputs, but once it is « active » it doesn’t use FMS data but the ILS receivers or the ILS and GPS receivers.

No need of the FMS neither for the approach, nor for AUTOLAND