It took days for the mutilated body of the woman, 22, to be found. A post mortem showed her "skull was broken".
Her mother told the BBC that her daughter was "a brave girl because she fought her rapists till the end".
"I want the death penalty for the culprits as a deterrent for others," she told BBC Hindi's Nitin Srivastava.
She added that the brutality of the attack shows that "the men don't deserve any mercy".
"It's difficult to forget the circumstances in which I had to identify her body. She was all naked and her face and upper part of the body was not identifiable," she said.
Residents in Sonipat district, where the victim's family lives, found the woman's decomposing body after they noticed stray dogs in the vicinity.
"We arrested two suspects the following day and they have confessed to the crime," superintendent of police Ashwin Shenvi told the BBC.
The doctor, who conducted the post mortem examination, told BBC Hindi that "the victim was murdered in a very brutal manner".
"Her head was crushed by a heavy object leading to fractures in most of the skull bones," he said.
The post mortem also showed she had been drugged before the attack. It is alleged at least one of the men knew her.
The victim's father said the suspects "had been stalking her for a while".
"She was not friends with these men. A few months ago, she and her mother even complained to the police about these men and apparently they apologised so the matter probably ended there," he said.
Scrutiny of sexual violence in India has grown since the 2012 gang rape and murder of a student on a Delhi bus.
However, brutal sexual attacks against women and children continue to be reported across the country.