The government will launch a TV, radio and newspaper campaign next week to tell people they could be jailed if caught employing children under 14, a spokesman said on Thursday.
A central ban on children working in restaurants, hotels and resorts as well as in homes comes into effect on Oct 10, a move that could impact the lives of millions.
"This national advertisement campaign will create awareness against child labour in these areas and will put the fear of law into the minds of people that violations could invite punishment," said ML Dhar, a spokesman for the union labour ministry.
The campaign will start in major cities on Oct 1 and then fan out across the nation. Its message will be a mix of emotional appeals to peoples' conscience as well as warnings of penal action, Dhar added.
Anyone employing a child under 14 as a maid or a house cleaner or in one of the thousands of open-air eateries that dot India's highways could be jailed up to two years or fined up to 20,000 rupees or both.
Officially, India has about 12 million child workers under 14, more than any other nation, but some voluntary groups put the number at close to 60 million.
Under India's Child Labour (Prohibition and Regulation) Act of 1986, children under 14 are already banned from working in industries deemed hazardous, such as fireworks and matchstick-making.
Activists say this ban has been poorly implemented.
The federal labour ministry has written to India's 29 state governments to be ready to house and school thousands of children who could be released from their jobs following the new ban, Dhar said.
UNICEF says the new law was much needed but warns it does not expect quick results for an age-old problem in India where many see nothing wrong with employing poor children.
"We cannot expect to have a process that will cleanse the child labour scenario overnight ... this will be a gradual process," said Carlotta Barcaro of the global agency's child protection unit in India.
"We do welcome this notification ... we have been screaming for such a law to ban child domestic labour," Barcaro said.
Dhar said that under the new ban, anyone could file a complaint with the police or labour authorities if they suspect children were employed as servants or in a tea shop.