What is National Monetisation Pipeline (NMP) plan? Why is this necessary?

A day after the government unveiled the National Monetisation Pipeline (NMP) worth Rs 6 lakh crore, former Congress President Rahul Gandhi on Tuesday accused Prime Minister Narendra Modi of bringing the process of selling the "crown jewel" assets built by his party in last 70 years. The NMP targets to raise Rs 6 lakh crore through asset monetisation of Central government, over a four-year period, from FY22 to FY25. Sitharaman said that the NMP is necessary for creating employment and triggering high economic growth.