http://indianexpress.com/article/india/du-student-kills-herself-boyfriend-used-caste-slurs-4611129/

Police said the woman and her boyfriend entered into a relationship three years ago after meeting at Gud Mandi, which comes under Model Town police station. The woman’s 32-year-old brother alleged that the accused had “sexually exploited” his sister. “When she asked him to marry her, he threatened her,” the brother alleged. According to the brother, the woman wrote in her suicide note that once she told the accused about her caste, “he started ignoring her and used caste-based slurs”. The family claimed that the woman eventually went to Roop Nagar police station to complain against the accused, but did not get help at first. Eventually, the woman and her brother were referred to Model Town police station, where they filed a complaint alleging “sexual exploitation”. DCP (northwest) Milind Dumbere said, “We have registered a case of rape based on the complaint.”

From the wording, the case seems to be, during the end of their relationship, she wanted marraige, he declined (maybe due to caste differences), and family did what normal people do, filed a rape case, the guy threatens nudes, she kills herself, the end.