Here we are supposed to use hazard in vehicle towing and the one being towed.
Civilians are not supposed to put beacon light [and/or extra lamps other than OEM lamps]. Even fitting fog lamps require endorsement from RTO.
Amber beacon is to be used in load carrying vehicles when it is carrying load.
Emergency vehicles can use red beacon [police and fire brigade]
All other including ambulance and VIP are to use Blue beacon only.
OT: Lot of hazard light misuse going on. People think they are for going straight and some use it for showing off. Keep them on throughout. One such guy knocked mass effect one day. He switched right indicator while hazard was on. I was overtaking him and he knocked me down, but I was slow, so was spared.
TAI please help educate people regarding the use of hazard,
Hazard is used when the car is parked in awkward locations [like blindspots and rear sticking out in road, etc, etc]. Second situation is previously described towing. Strict no, no when normal driving, and during rain. Another permissible situation is when the vehicle driven slow due to some issues [almost equivalent situation to towing].