Ankita had allegedly been harassed by the man accused, Shahrukh Hussain.
Right-wing Hindi groups alleged Hussain wanted to commit "love jihad", a controversial term used by radical groups to accuse Muslim men of converting Hindu women by marriage, the BBC reports.
Her father Sanjeev Singh said, "Shahrukh used to tell her – marry me, accept Islam, else I will make your life hell," the Daily Mail reports.
She rejected his advances and he allegedly harassed her for days by calling her phone repeatedly.
"He called me again around 8pm on Monday and told me that he would kill me if I did not talk to him," Ankita said before she died.
Shahrukh Hussain was seen smirking in a video as he was arrested. Photo / Twitter
"I informed my father about the threat, after which he assured me that he would talk to the man's family."
She was sleeping near a window and it's alleged Hussain poured petrol on her before setting her alight.
"After having our dinner, we went to sleep. I was sleeping in another room," Ankita said.
"I experienced a sensation of pain in my back and could smell something burning. I found him running away when I opened my eyes.
"I started screaming in pain and went to my father's room. My parents doused the fire and took me to the hospital," she said just hours before she died.
She was rushed to the hospital with 90 per cent burns and died five days later.
The Year 12 student was an aspiring police officer.
"She wanted to get a government job so that she could help her father support the family," her grandmother Vimla Devi told the BBC.
A video of her alleged attacker, Shahrukh Hussain, went viral after he appeared to be smirking as he was led away by police.
An associate who allegedly provided the petrol for the attack was also taken into custody.
It's the latest in a number of horrific crimes against women in India that have made headlines recently. A 16-year-old girl claimed she was raped by hundreds of men and a 13-year-old girl said police attacked her when she reported a sexual assault.
It's been reported that a rape occurs every 18 minutes in India and more than 28,000 women and girls were raped in a single year in the country.
The alleged attack on Ankita by the scorned suitor has inflamed discontent in the country where there is simmering religious tension between India's Muslim and Hindu-majority populations.
Police superintendent Amber Lakra said the crime was not one of religion and police were on high alert.
"We are being especially vigilant as the boy and girl belong to different religions," he added.
Authorities imposed the draconian anti-riot section 144, which prohibits gatherings of more than four people in an area in order to "maintain law and order" amid widespread protests.
Authorities also imposed section 144 earlier this year when Kanhaiya Lal was allegedly partially beheaded by two men inside his tailoring shop in Udaipur, Rajasthan.
