Of the 35 accused in the case, five had died during the pendency of trial.
While Dharmarajan was sentenced to life, the remaining were sentenced to varying terms of rigorous imprisonment up to 13 years and fine by a division bench, comprising justices K T Sankaran and M L Joseph Francis, which delivered the judgement on separate appeals filed by the accused.
Of the 35 accused in the case, five had died during the pendency of trial
For default of sentence, the accused would have to undergo an additional three months RI.
The case relates to the abduction and sexual exploitation of a minor girl from Suriyanelli in Kerala's high range Idukki district by several persons in 1996.
The bench rejected the plea of the accused that the victim was 'deviant', and that she could have escaped during her captivity.
The judges said there was no embellishing in the evidence of the victim which runs to 598 pages and it was totally accepted.
"There are materials to show that her evidence is true. She was mercilessly and brutally raped," the court held.
Dharamarajan, Raju, bus conductor and first accused and second accused Usha procured her and she was subjected to rape by other accused, the court held.
Dharmarajan, who had been absconding, was later arrested.
While the trial court had convicted all the accused on charges of rape, gangrape and kidnapping, the High Court had acquitted all but one.
On an appeal filed by the state government and the victim, the Supreme Court had ordered the High Court to consider afresh the appeal filed by the accused.
The prosecution case was that the girl, who was studying in school, was enticed, abducted and sexually exploited by a bus conductor on January 16, 1996.