"There is no evidence to show that the death penalty acts as a deterrent for sexual violence or any other crime", said Asmita Basu, a top official of the global rights organization in India.
Rights activists, opposed to death penalty, said execution will not eradicate violence against women. The Delhi High Court upheld that verdict in 2014.
Their daughter - a physical therapy student who became known as "Nirbhaya" which means "fearless" - had gone to see the "Life of Pi" with a male friend at a popular New Delhi mall cineplex on the night of December 16, 2012 when they boarded a private bus to make their way home to a neighborhood on the outskirts of India's capital city. She died on December 29 in a Singapore hospital where she was flown to by the government.
The victim's mother, who was present in the court when the order was announced, said she hopes the convicts are hanged "as soon as possible".
A bench comprising Chief Justice of India Dipak Misra and justices R Banumathi and Ashok Bhushan rejected the review petitions filed by Mukesh (29), Pawan Gupta (22) and Vinay Sharma (23), saying the convicts had made no grounds for a review of the May 2017 judgment upholding their capital punishment.
"There is more fight ahead, but we have got justice once again".
The third declaration was recorded by a metropolitan magistrate on December 25 and was mostly through gestures.
With regard to the second declaration, the counsel appearing for the convicts submitted that in the police diary there was no mention of it.
The six-strong gang beat the man unconscious before raping and torturing Singh with an iron bar as the private bus drove loops through the Indian capital.
She was also severely assaulted before being thrown out on the road.
Three of the rest of the four convicts appealed to the Supreme Court to change its own death sentence into life imprisonment.
The bus driver, the fifth suspect in the crime, was found hanging in his cell in a prison in March 2013, months before the suspects were convicted.
A juvenile accused was convicted by a juvenile justice board. A juvenile in conflict with the law was tried by a special court and has already served three years in a reform home.