The bill was introduced by the government amid opposition's criticism.
The constitutional provision to provide 10 per cent reservation in government jobs and education to economically backward section in the general category has come into force on Monday, a government notification said.
The Constitution (103 Amendment) Act, 2019 received the assent of the President on Saturday.
"In exercise of the powers conferred by sub-section (2) of section 1 of the Constitution (One Hundred and Third Amendment) Act, 2019, the Central government hereby appoints January 14 as the date on which the provision of the said Act shall come into force," a gazette notification by the Ministry of Social Justice and Empowerment read.
The Act amends Articles 15 and 16 of the Constitution, by adding a clause which allows states to make "special provision for the advancement of any economically weaker sections of citizens".
These "special provisions" would relate to "their admission to educational institutions, including private educational institutions, whether aided or unaided by the state, other than the minority educational institutions".
It also said the reservation would be "in addition to the existing reservations and subject to a maximum of 10 per cent of the total seats in each category".
The bill was passed by Parliament on January 9.
"For the purposes of this article and article 16, ''economically weaker sections'' shall be such as may be notified by the State from time to time on the basis of family income and other indicators of economic disadvantage," the notification read.
Amendment of Article 16 stated, "Nothing in this article shall prevent the State from making any provision for the reservation of appointments or posts in favour of any economically weaker sections of citizens other than the classes mentioned in clause (4), in addition to the existing reservation and subject to a maximum of ten per cent of the posts in each category."
While introducing the bill in Parliament, Union minister Thaawarchand Gehlot had said that at present, the economically weaker sections of citizens have largely remained excluded from attending the higher educational institutions and public employment on account of their financial incapacity to compete with the persons who are economically more privileged.
According to the objects of the bill, "The directive principles of state policy contained in Article 46 of the Constitution enjoins that the State shall promote with special care the educational and economic interests of the weaker sections of the people, and, in particular, of the Scheduled Castes and the Scheduled Tribes, and shall protect them from social injustice and all forms of exploitation."
"With a view to fulfil the mandate of Article 46, and to ensure that economically weaker sections of citizens get a fair chance of receiving higher education and participation in employment in the services of the State, it has been decided to amend the Constitution of India," the statement of objects of the bill said.