"As a woman and mother, I understand how you feel. I appeal you to remain calm and help strengthen our collective resolve to fight the menace of violence against women," Gandhi, who is also the United Progressive Alliance chairperson, said in a televised address.
"Today all Indians feel as they have lost their own beloved daughter, their cherished sister, a young woman of 23 whose life full of hope, dream and promise was ahead of her. Our hearts go out to her parents, family, the whole country shares their pain," she said.
Appealing for peace and calm in wake of the tragic incident, Gandhi said, "Today we pledge that she will get justice and that her fight will not go in vain".
The Congress President said that the tragedy 'strengthens our resolve to fight with all our might and with all the powers of our laws and our administration for the safety and protection of all women of our country and to ensure swift and fitting punishment for the perpetrators of such acts.
"It deepens our determination to battle the pervasive shameful social attitudes and mindsets that allow men to rape and molest women and girls with such impunity."
As people hit the streets expressing their outrage over the tragedy, Gandhi said "to all of you who have expressed their anger and anguish publicly, who have poured out in her support, I want to assure you that your voice has been heard."
Gandhi had on Friday sought speedy action against theperpetrators of the 'barbarous' attack and had hoped the victim undergoing treatment in Singapore recovered.
Choosing to skip her customary New Year wishes on the sidelines of the 127th Foundation Day of Congress at the All India Congress Committee headquarters in New Delhi on Friday, Gandhi had said, "Not so today because our thoughts are with the young woman, who is fighting for her life after the barbarous attack".
She had added, "Our only wish today is that she recovers and comes back to us and that no time is lost in bringing the perpetrators of such a barbarous act to justice".
The Congress chief had earlier shot off strongly-worded letters to Home Minister Sushilkumar Shinde and Delhi Chief Minister Shiela Diskhit wanting firm steps for the security of women in the national capital, describing the incident as a 'matter of shame'.