She was taken to a local hospital and then referred to Delhi hospital due to seriousness of the burn injuries, they said, adding she died at the Delhi hospital.
The three accused - Lokendra, Pradip and Sonu - were arrested. The fourth accused was Lokendra's wife Archana, who had helped them, police said.
"Police only got information today and has arrested the four accused," said senior police officer.
According to the police, the accused raped her while she protested, which enraged them to set her on fire.
The accused had made an MMS clip of rape and used to extort money from the victim. The tenth standard student twice paid Rs 5,000 to them, police said.
Earlier victim had complained to police but due to political connections, no action was taken, they said.