Which airports have ILS Cat IIIC?
This is not implemented anywhere in the world.

Wikipedia:


  As of 2012 this category is not yet in operation anywhere in the world
  as it requires guidance to taxi in zero visibility as well. Category
  IIIc is not mentioned in EU-OPS.


Airliners:


  As far as I know NO airport in the world currently offers catIIIc as
  it has the most ridiculous minima both in the horizontal and vertical
  plane ...