"We are busy with the revival right now... Both the Northern and Eastern grids have collapsed. Please allow us to address the problem," VK Agrawal, the general manager of the northern grid, said.
In New Delhi, the metro train system came to a standstill and many traffic lights were out for the second day in a row after the northern grid failed on Monday in the worst power outage in a decade.
"Drivers of all the metro trains have been asked to stop at the stations. No passengers will be allowed in the metro station until power is restored," a metro spokesperson said.
About 400 trains were affected by the power outage, a spokesperson for the railways said.
In the east, the city of Kolkata was without power as were most parts of the surrounding state of West Bengal, an official at the West Bengal State Electricity Supply Corporation, B Mukherjee, confirmed.
Hospitals, airports hit
The eastern grid covers five states including West Bengal, Bihar, Jharkhand, Sikkim, and Orissa.
"This is a big crisis. We are working to restore power. Many states overdraw power and this has caused a complete collapse in eastern and northern India," said a senior official at the ministry of power in New Delhi.
On Monday, the northern grid collapsed for six hours, causing travel chaos and widespread inconvenience in nine states including the capital New Delhi.
Major hospitals and airports in the region were able to function normally on emergency back-up power, but train services were severely disrupted.
Power Minister Sushilkumar Shinde called it a "failure" but he also boasted that India had been quick to restore power, unlike the United States which took days to restore electricity a 2003 blackout on its eastern seaboard.
He and the rest of the government woke up on Tuesday to a barrage of calls for urgent reform of the power sector.
Leading the charge were business lobby groups who said Monday's outage - the worst to hit the country in a decade - underlined the government's inability to address India's perennial electricity shortfall.
"The increasing gap between electricity supply and demand has long been a matter of concern," said Chandrajit Banerjee, director general of the Confederation of Indian Industry (CII).
The CII, Banerjee said, has "consistently highlighted" the need for urgent steps to improve supplies of coal to thermal power plants and reforming state distribution utilities.
"This latest outage is just an urgent reminder for addressing these issues as a priority," he added.