The woman was attacked by a group of men in the state of Uttar Pradesh, including two of the five men she had accused of gang-rape last year who were out of custody on bail.
Five men were arrested in connection with the burn attack.
The 23-year-old woman suffered extensive injuries and was airlifted Thursday from Uttar Pradesh to Safdarjung Hospital in New Delhi, where she died late Friday of cardiac arrest, according to Dr. Shalab Kumar, head of the hospital's burn unit.
Priyanka Gandhi, the general secretary of the opposition Congress party, faulted the Uttar Pradesh government, led by Prime Minister Narendra Modi's ruling Bharatiya Janata Party, for failing to provide the woman with security, even after a similar case in the state in which a woman who accused a BJP lawmaker of rape was severely injured in a vehicle hit-and-run incident.
The burn victim's death came on the same day police in the southern state of Telangana fatally shot four men being held on suspicion of raping and killing a 27-year-old veterinarian after investigators took them to the crime scene. Their deaths drew both praise and condemnation in a case that has sparked protests across the country.
The woman's burned corpse was found last week by a passer-by near the city of Hyderabad, India's tech hub, after she went missing the previous night.
Police took the four suspects , who had not been charged with any crime, to the scene to help them locate the victim's phone and other items, officials said. They said that the men grabbed police firearms and began shooting, and were killed when police returned fire.
The Telangana High Court ordered authorities to preserve the bodies of the suspects and submit a video of the autopsies ahead of a court hearing set for Monday.
Separately, the National Commission on Human Rights, an autonomous body within India's Parliament, sent a fact-finding mission to the crime scene and mortuary where the suspects' bodies were held on Saturday amid questions from opposition lawmakers about the circumstances of the suspects' deaths.