Despite a ban on gatherings of more than five people, thousands poured into the heart of the capital to vent their anger.
Police used tear gas and batons to hold back crowds marching on the president's palace, as they had the day before. About 30 injured people, including policemen, were treated in hospital.
The 23-year-old victim of the attack on December 16 was beaten, raped for almost an hour and thrown out of a moving bus in the city. She is still in a critical condition but is responding to treatment. Six men have been arrested in connection with the assault.
New Delhi has the highest rate of sex crimes of India's major cities, with a rape on average every 18 hours, police say.
Most sexual assaults go unreported but last week's attack triggered the biggest protests in the capital since 2011's demonstrations against corruption that rocked the government of Prime Minister Manmohan Singh.
Despite promises of better policing, protesters, mainly students but also including housewives, are demanding more measures to keep women safe.