34 out of 86 inmates broke out of the facility in Munger district of Bihar on Sunday, an officer said. 12 returned in the hours after the daring escape.
"The inmates broke the iron grills and the metal gate and fled in an overnight escape," Ashish Bharti, Munger police chief, told news agency AFP.
Many of the escapees have either been convicted or are awaiting trial for serious offences such as murder, rape and theft, the officer added.
Police are investigating the breakout and a manhunt is underway for the escapees.
About 31,000 offenders below the age of 18 are kept in juvenile homes intended for reforming the delinquents, according to official statistics.
The homes have no armed guards and inmates often sleep in dormitories instead of individual cells.