Police used water cannon and tear gas to disperse an angry crowd numbering in the thousands from the Raisina Hill area of New Delhi.
India's home secretary told reporters the government was already working on the protesters' demands, including improving passenger safety on buses by deploying undercover police and banning curtains and other window coverings.
"I'm not justifying use of tear gas," R.K. Singh said, "Government is hearing them (the protesters) loud and clear."
Raisana Hill is not far from the scene of the alleged crime, The Indo Asian News Service said.
A 23-year-old woman and a male companion said they were on a private charter bus in the area when they were jumped by a group of men who beat them severely with an iron rod and then sexually assaulted the woman.
Police arrested six suspects in the alleged attack. About 600 rapes were reported in New Delhi this year, one of the highest rates of sexual assault in India, Voice of America said.