In India, the right to free legal services is a fundamental right guaranteed by the Constitution of India and further elaborated through legislation and judicial interpretation. The Legal Services Authorities Act, 1987, is the primary statutory instrument governing the provision of free legal services.
Following are entitled to free legal services:

A. Economic Disadvantage:
The foremost eligibility criterion for receiving free legal services is the financial incapacity to afford legal representation. The Income Criteria (as per the Legal Services Authorities Act, 1987) stipulate that a person whose annual income does not exceed ₹1,00,000 (this limit can vary according to state-specific norms) is eligible for free legal services.

B. Socially and Economically Disadvantaged Groups:
The law also specifically targets certain social groups that are more likely to face legal challenges but may lack the means to secure adequate legal representation:
Scheduled Castes (SCs) and Scheduled Tribes (STs).
Backward Classes.
Women (in cases related to domestic violence, matrimonial issues, etc.).
Children (for matters related to child abuse, custody disputes, etc.).

C. Vulnerable and Special Categories of Persons:
Mentally ill persons: Those who are mentally ill or suffer from severe physical disabilities are entitled to free legal services, especially in cases involving criminal charges or civil disputes.
Persons in custody: Undertrials, prisoners, and persons in detention are eligible for free legal aid, ensuring their right to a fair trial.
Victims of human trafficking or beggars: Those who are victims of trafficking or forced into begging are entitled to free legal services.

In Khatri v. State of Bihar (1981): The Supreme Court held that a person who is unable to afford a lawyer must be provided with free legal aid. The case underscored the right to legal representation in criminal cases, ensuring that even indigent accused persons have access to justice.

Under Section 12 of the Legal Services Authorities Act, 1987, the following categories of people are entitled to free legal services in India:

1. Women and Children
All women, regardless of income or caste.
Children (under 18), including juveniles and victims of trafficking or sexual abuse.

2. SCs and STs
Members of the Scheduled Castes (SC) or Scheduled Tribes (ST).

3. Victims of Human Trafficking or Begging
As defined under relevant laws or identified by authorities.

4. Persons with Disabilities
Including those with mental illness (as per the Mental Healthcare Act, 2017, and Rights of Persons with Disabilities Act, 2016).

5. Victims of Mass Disaster, Ethnic Violence, Caste Atrocities, or Natural Calamities
Including riots, earthquakes, floods, etc.

6. Industrial Workmen
As defined under the Industrial Disputes Act, 1947.

7. Persons in Custody
This includes:
Undertrial prisoners
Persons in police custody
Juvenile homes or protective homes

8. Persons with an Annual Income Below Prescribed Limit
The income ceiling is fixed by State Legal Services Authorities (varies by state), for example:
₹3 lakh p.a. in the Supreme Court (as per NALSA)
Usually ₹1.5–2 lakh p.a. in State and District courts

Legal Authority:
Article 39A of the Constitution directs the State to ensure free legal aid.
Legal Services Authorities Act, 1987: Provides statutory backing.
How to Apply:
Approach Legal Services Clinics, District Legal Services Authority (DLSA), or State Legal Services Authority (SLSA).
Apply online via https://nalsa.gov.in
Fill out a form with basic details and proof of eligibility.