Criticism has mounted over the lack of planning ahead of the coronavirus shutdown, which was introduced with less than four hours' notice.
Many of India's 1.3 billion citizens have been left jobless and hungry.
Tens of thousands of migrant labourers have been forced to walk hundreds of kilometres to their native villages.
In his weekly radio address PM Narendra Modi apologised for the impact of the strict stay-at-home measures.
But he said there was "no other way" to stop the rapid spread of the virus.
"Especially when I look at my poor brothers and sisters, I definitely feel that they must be thinking, what kind of prime minister is this who has placed us in this difficulty?
"I especially seek their forgiveness," he said.
"Possibly many would be angry at me for being locked in their homes.
"I understand your troubles but there was no other way to wage war against coronavirus... It is a battle of life and death and we have to win it."
People are banned from leaving their homes for three weeks under the "total lockdown" measures announced on Tuesday. All non-essential businesses have been closed and almost all public gatherings are banned.
It has sparked an exodus from major cities such as Delhi, where thousands of migrant workers are setting out on long journeys back to their home villages after transport was stopped.
One worker died on Saturday after he attempted to walk a 168 mile (270km) journey back home, a police officials told Reuters news agency.