PIL aims to provide legal assistance to marginalized and disadvantaged sections of society who may not have the resources or knowledge to pursue their legal rights through conventional means.

The Olga Tellis case, also known as the pavement dwellers' case, is widely regarded as the starting point of PIL in India. It established the locus standi of social action groups to file petitions on behalf of marginalized communities.

The locus standi principle in PIL enables individuals and groups, even if they are not directly affected by a particular issue, to bring legal challenges on behalf of the public interest.

PIL cases typically focus on issues of public importance and social justice, such as environmental protection, human rights violations, and consumer rights. Taxation disputes, on the other hand, are usually handled through regular legal channels.

PIL has played a significant role in expanding legal rights in India by securing the recognition of new fundamental rights, broadening the scope of existing rights, and enhancing the enforcement of legal rights.

The M.C. Mehta case, also known as the Ganga pollution case, led to the Supreme Court recognizing the right to a clean environment as a fundamental right under Article 21 of the Indian Constitution.

PIL has been instrumental in addressing issues of social justice in India by providing legal recourse to marginalized communities, promoting the enactment of progressive social welfare legislation, and ensuring the implementation of government policies aimed at achieving social justice.

PIL in India faces challenges such as lack of awareness among marginalized communities, limited resources and capacity of legal aid organizations, and judicial reluctance to intervene in policy matters.

To enhance the effectiveness of PIL in promoting social justice in India, it is essential to increase public awareness, strengthen the capacity of legal aid organizations, and encourage judicial activism in cases involving social justice issues.

Legal aid organizations play a crucial role in promoting PIL by providing legal assistance to marginalized communities, conducting research and advocacy on social justice issues, and litigating PIL cases on behalf of public interest.

The Vishaka case resulted in the Supreme Court issuing landmark guidelines for the protection of women from sexual harassment at the workplace, known as the Vishaka Guidelines.

PIL has played a significant role in protecting environmental rights in India by securing the recognition of the right to a clean environment as a fundamental right, promoting the enactment of environmental protection laws and regulations, and ensuring their effective enforcement.

The Bandhua Mukti Morcha case resulted in the Supreme Court issuing comprehensive guidelines for the rehabilitation of bonded laborers, including measures for their release, compensation, and social integration.

PIL has been instrumental in addressing consumer rights issues in India by promoting the enactment of consumer protection laws, facilitating the establishment of consumer courts and tribunals, and providing legal recourse to consumers seeking redressal for their grievances.

PIL plays a vital role in promoting social justice in India by providing a mechanism for marginalized communities to access justice, holding the government accountable for its actions and policies, and promoting the development of progressive social welfare legislation.