"We want him to be hanged. A despicable game has been played on us. We will appeal," he told reporters outside the board shortly after it gave the verdict.
"I am not happy with this verdict. It would send a wrong message that a juvenile can get away even after committing a brutal crime," said the mother.
She demanded the most stringent punishment for the juvenile accused.
The victim's father said he would move the higher court against the order, as "our hopes of him getting stringent punishment has been dashed by the JJB verdict".
Visibly upset, he said it was a crime in India to be born as a girl.
"After this, I can say that female foeticide is right as those who do it, they don't have to experience the pain with which we are going through."
The JJB has let him go with just three years of jail, but one thing I can assure you that he would become a criminal and time would tell, he added.
The girl's younger brother also expressed disappointment over the quantum of punishment to the juvenile accused saying, "I had seen his face, he has no remorse, no shame and no fear on his face."
It is wrong to give him just three years punishment, even when he was convicted for rape, robbery and murder, he said, adding that too from the day he was arrested.
"Children above 16 years of age have senses and they know what is wrong and what is right. He was violent even in the Juvenile home, where he was kept, as there were reports of him having attacked inmates with a blade there. I have seen my sister dying, every minutes, every second. I will approach higher courts," he said.