Hundreds of men accused of sexual violence towards women have been allowed to stand in Indian elections in the last five years, including more than 30 charged with rape.

The figures were released in Delhi by the Association for Democratic Reforms, a respected thinktank, and were based on court records and electoral declarations filed by the candidates.

Although most of the men concerned were contesting state elections, the report found dozens of men facing criminal investigations for assault, "outraging the modesty of a woman" and other charges had been selected by major parties to campaign for seats in the national assembly.

The news comes as demonstrations across India continue following the gang rape of a 23-year-old student in Delhi on Sunday. Six men have been arrested for the attack. The victim, who sustained severe intestinal injuries, remains in a critical condition in hospital. It was reported that she had regained consciousness but was still extremely weak. Doctors have described her as "a fighter".

The attack has dominated the news agenda in India all week, unleashing a wave of anger and shock directed largely at police officials as well as senior politicians such as Delhi's chief minister, Sheila Dikshit. A crowd marched to the residence of the president, Pranab Mukherjee.

Among the Bollywood celebrities who have expressed dismay was A R Rahman, who composed the soundtrack to Oscar-winning hit Slumdog Millionaire. "If you don't fix it now, it is shame for the nation," he said.Officials attempted to reassure the public.

"The kind of policing we will have, we will ensure that everyone, man or woman, can move freely in any part of Delhi in both day and night," said RK Singh, the most senior civil servant in the Indian home ministry.

A particular grievance voiced by protesters and in the media has been that about a tenth of Delhi's 80,000 police officers are posted to protect the capital's top officials, politicians and diplomats. In India, the number of armed officers deployed is often taken as an indicator of an individual's power and influence.

"It is outrageous. They are guarding people who don't need to be guarded while the vulnerable are being left alone," said protester Ayesha Malik, 31, a housewife who joined the protest.

Professor Dipankar Gupta, a sociologist at Shiv Nadar University, Noida, said the response to the attack was partly due to the background of the victim as well as the brutality.

"There is a strong resonance. She doesn't come from a particularly wealthy family. Her parents had sold their land and paid for her education rather than a dowry. The attack happened in a normal part of Delhi, at 9pm and no one can possibly allege that she was behaving in a way that was 'not in keeping with Indian traditions' and all that junk," Gupta said.

Rape victims in India often face claims that they provoked their attackers.

Anil Bairwal, one of the authors of the thinktank report, said the true number of state and national parliamentarians and candidates facing charges of sexual violence could be far higher, as most attacks were registered without reference to gender.

"If the parliamentarians who are discussing these kind of problems have themselves given tickets to people like this then you can legitimately ask if they are serious about punishing this kind of crime," Bairwal said.

High proportions of Indian politicians have often serious criminal charges outstanding against them. Though some charges are undoubtedly unfounded, as judicial process is often used to smear political opponents, and the police force in many states is highly corrupt, Indian analysts frequently warn of increasing criminal involvement in politics.

Many of the politicians facing rape allegations came from poor northern states with poor records for law and order, such as Uttar Pradesh and Bihar. In the most recent national elections, the report said, political parties put forward six candidates who declared they had been charged with rape – though none won seats.

Neeraj Kumar, chief commissioner of Delhi, explained the rise in the number of recorded rape complaints in the capital, which has a population of around 15 million, from 564 in 2011 to 661 this year, as due to "more and more women feeling empowered to come forward and lodge reports".