NEW DELHI: The exercise to update the National Population Register NPR ) and the first phase of the Census 2021 will not be held as scheduled due to the 21-day lockdown announced by Prime Minister Narendra Modi , officials said on Tuesday.Both the exercises were supposed to be carried out from April 1 to September 30.Due to the prevailing situation, the NPR and Census exercises have been deferred till further orders, a senior home ministry official said.The Prime Minister has announced a 21-day lockdown across the country from Tuesday night due to the outbreak of the coronavirus.