An Indigo flight at the gate after landing in heavy fog at Bangalore airport using the CAT IIIB system
Finally Bangalore airport commissions the CAT IIIB system which allows planes to land even with minimal visibility

Bangalore, January 22 2021: Kempegowda International Airport, Bengaluru (KIAB/ BLR Airport) recorded its first landing under CAT IIIB conditions on the morning of Thursday, January 21, 2021.
Radiation fog set in during the early part of the day, resulting in a rapid drop in visibility to 200 metres. During this time, IndiGo flight 6E-6389 from Lucknow made a successful touchdown at 0741 hours.
The South Runway can facilitate aircraft landing with an RVR as low as 50 metres and take-offs at 125 metres. Before the upgrade, the permissible visual range was 550 metres and 300 metres, for landing and take-off, respectively.
This upgrade by BIAL is expected to reduce disruption in operations and would immensely benefit passengers during inclement weather conditions.
The instrument landing system (ILS) is a radio navigation 
system that provides short-range guidance to aircraft to allow
them to approach a runway at night or in bad weather.(wiki)
What is a CAT 3B landing?
A precision instrument approach and landing operation with a
decision height (DH) lower than 15m (50 feet) or no DH and a 
Runway Visual Range (RVR) lower than 175m (600 feet) but not
less than 50m (200 feet).