Fifty lakh children eke out a livelihood in the country, of whom 17.5 lakh are in Uttarakhand, according to the National Sample Survey Organisation (NSSO).
The second-largest share of child labourers comes from West Bengal (5.5 lakh), Rajasthan (4.05 lakh) and Gujarat (3.9 lakh), the NSSO estimated on the eve of the World Day against Child Labour Wednesday.
"Though the ban on child labour in homes and in eateries has been there since 2010, thousands of children work as domestic workers or in 'dhabas' and even in factories under hazardous conditions," said Thomas Chandy, CEO, Save the Children.
International Labour Organisation (ILO) has marked 2013 as the year to combat child domestic labour, which has become a growing menace in India.
"Immediate enforcement of the provisions of Child Labour (Prohibition and Regulation) Act, 1986, and all other related acts need to be implemented to prevent the employment of children in bidi rolling or other hazardous occupations," said Bhavna Mukhopadhyay, executive director, Voluntary Health Association of India.
Child labour in India is governed by the Child Labour (Prohibition and Regulation) Act, 1986, to which an amendment was also proposed.
Puja Marwaha, CEO, Child Rights and You (CRY), said: "A child of 14 or 18 years is equally if not more vulnerable to abuse and exploitation as a child of 12 or 13 years. The National Policy of Children 2012 declares that all children from zero to 18 years need to be protected and provided with all the facilities of health, education, nutrition and protection."