During cruise aircraft encountered turbulence and one of the cabin crew received serious injury. Contributory Factors Weather and actions of cabin and the cockpit crew in not following the laid down SOP were the contributory factors that led to the accident. Probable causes of the accident 1. The weather en-route TRZ ? BLR was turbulent, since Weather Radar detects only water droplets and not dry air turbulence. If tilt management is not appropriate pilots could misinterpret the weather target displayed and could inadvertently minimize convective thunderstorm. 2. Anticipating turbulent weather the crew switched ?ON? the seat belts sign, but failed to announce over PA or inform the cabin crew of possible turbulence ahead. 3. The cabin crew too did not enquire from the Captain the reason for the Seat belts signs ON. This is a serious communication failure between the cockpit and cabin crew. Indigo airlines addressed this issue by carrying out amendments in their safety and emergency manual, SEA, Part Three Section 3.12, Turbulence dated 15 September 2021 after this accident. 4. The sudden drop in altitude by 250 feet, owing to the turbulence when the aircraft encountered weather, led to the cabin crew L1, falling down and getting her leg fractured. The cause of the accident was aircraft entering turbulent weather and both the Cockpit Crew and Cabin crew not following assigned SOPs, while flying through Turbulence.