A New Delhi court was set to deliver the first verdict on Thursday on one of five suspects on trial over the fatal gang-rape of a student on a bus, which triggered an outcry in India.

The juveniles' court in the capital has finished hearing the case of a teenager, aged 17 at the time of the brutal assault in December, who faces a maximum sentence of three years in a correctional facility if found guilty.

The defending counsel said he would announce his next move once the verdict, which many fear could spark fresh demonstrations, is out later Thursday.

"I am awaiting the judgement which will come anytime between 10:30 am and 2:00 pm (0500 GMT and 0830 GMT)," said Rajesh Tiwari, a lawyer defending the juvenile who cannot be named for legal reasons.

"It is really difficult to say how I am feeling just now but I will react once the verdict is out," the lawyer told AFP.

The juvenile on trial can be sent to a correctional facility for a maximum three-year term, which includes the time he has already spent in custody while waiting for the verdict.

The verdict is likely to cause further anger in a country attempting to turn a rising tide of violence against women and which has passed a new law toughening sentences for adults convicted of sex crimes.

The victim's family led calls for the teenager to be tried as an adult, alongside five men initially arrested over the savage crime on December 16, which led to weeks of protests in the capital and elsewhere.

The trial of four adult suspects continues but is expected to wrap up in the next few months, with the men facing a possible death sentence if convicted of rape and murder.

The fifth adult, alleged ringleader Ram Singh, died in jail in an apparent suicide.

A government panel set up after the Delhi gang-rape to recommend changes to sex crime laws rejected calls to lower the age at which people can be tried as adults from 18 to 16.

Delhi High Court lawyer Vishwendra Verma, who is not connected with the case, underlined that the juvenile court could not award more than three years detention, which is not considered a punishment.

"It is an act to reform the child," the legal expert told AFP.