Key reason seems to be "Flight to safety" due to economic and Ukraine led uncertainties. Wherein, investors appears to be moving their money out of non-US economies to US.
Silver lining: Unlike the previous such like situations, this time the fall in Rupee has been relatively less than most other comparable currencies. The reason could be India's stronger macro-fundamentals.
From 1991-2020: Rate of Rupee fall was 4.2%.
Between Apr 2020-Apr 2022: Rupee was generally stable at ₹75-76 per US$. Thus with 4.2% annual depreciation Rupee would have been at around ₹82 per US$.
PS: Once the Ukraine uncertainty gets over Re may be expected to reverse as currently US inflation is > India.