According to the Saubhagya dashboard there are 21.3 crore households in India of which only 18,734 households are un-electrified. Which means 21.29 crore households use and pay for electricity. Assuming that 50% of all electrified households participate in the PM's call

Assuming 2 LED bulbs (to be conservative) will be shut for 9 mins in each households for this. Assuming average cost of energy to be Rs.2/kWh since many households using electricity for residential use may be paying BPL rates also.

This would mean a loss of Rs. 64 crore for the electricity utilities in just 9 minutes. Since this is only residential lighting demand, grid stability wont be an issue. @naukarshah since you asked. Bhakts of course will say this much money is okay to blind the virus or something