Police said they had gone through hours of CCTV footage from the night in Bengaluru, a southern IT hub seen as relatively safe for women, and had found no evidence to back up the reports.
"We started looking into the whole video footage from approximately 45-60 cameras," Praveen Sood, the police commissioner of Bengaluru city, told journalists.
"It takes time, the whole team was looking at the camera footage and looking for molestation in the video. We could not find any sign of molestation," Sood said.
Local reports featured testimony and photos of victims cowering from their attackers or fleeing for safety while video footage circulated on social media showed women screaming for help.
Police have referred to the interviews and social media accounts of eyewitnesses and women who were allegedly molested to file six separate cases, Sood said.
The attacks in Bengaluru have drawn comparison with last year's mass sexual assaults at New Year's celebrations in the German city of Cologne, where police were also accused of losing control.
The state government of Karnataka, whose largest city is Bengaluru, has faced severe backlash over its handling of the incident, particularly after a local minister criticised the women for dressing "like westerners".
India has come under intense scrutiny in the past for shocking levels of sexual assault against women, notably in December 2012 when a student was gang-raped on a bus in New Delhi and later died of her injuries.
