Because skyrocketing energy and commodity prices that look like will still going on quite long by seeing the determination of Russia and Ukraine in their war.
Currency depreciation will make energy cost getting expensive which is not good for Indian industry competitiveness, and also with commodity price increase, lower income people will get the effect, not good for both economic and political point of view.
Indian government also worried with their private sector that has many debt from foreign loan and foreign denominated bond.
The pledge I believe for long term, and it is good to scare the speculators before it is too late
I think it will be a combination of interest rate hike and market intervention to defend Rupee