Former government officer Sanji Ram, believed to be the mastermind, was among those sentenced to life.
The Jammu and Kashmir police on Monday said it may challenge the acquittal of the seventh accused in the Kathua gang rape and murder case, in which three persons were sentenced to jail for life and three others for five years each.
Inspector General of Police Ahfadul Mujtaba of the state police Crime Branch, which investigated the gang rape and murder of an eight-year-old girl of a nomadic tribe in Jammu and Kashmir's Kathua in January 2018, said the police will challenge the acquittal of the seventh accused "if needed".
The IGP talked of challenging the acquittal of one accused while welcoming the conviction of six others.
Six of the seven accused in the case, including the caretaker of a temple where the crime took place and a special police officer, were convicted by a Pathankot court on Monday.
The court acquitted seventh accused Vishal, the son of main accused Sanji Ram, giving him the "benefit of doubt", said Farooqi Khan, who represented the victim's family in the court.
"We welcome this verdict except that one person has been acquitted," said Inspector General of Police Ahfadul Mujtaba of J&K Police's Crime Branch.
The IGP said the police were yet to get the copy of the judgment.
"Once we examine it and if needed, we will challenge it in the Punjab and Haryana High Court," said Mr Mujtaba.
The case was tried by a Pathankot court in Punjab as the same had been transferred there amid a highly polarised communal situation.
"Actually (seventh accused) Vishal had taken the alibi that he was not present there (at the scene of the crime), though we have eyewitnesses' account of his presence there. We have eyewitnesses who said he was very much there on the day of the incident," the IGP said.
The court, however, has accepted his alibi, said the IGP, adding the police would examine under what circumstances Vishal was acquitted.
Asked how the police tackled the difficult situation and carried out the investigation amid the highly polarised atmosphere, the Crime Branch chief said, "Any professional investigating agency will go by witnesses and evidence."
"When you go to a court of law, it has to be judged as per the evidence. You cannot bring a cock and bull story and present it to the court. You have to work on the merits and the evidence of the case," he said.
Terming the case as a "challenging" one, the IGP said the police had presented 114 prosecution witnesses before the court despite several problems.
"Ensuring the witnesses to be present in the court every day was quite a challenge, so was ensuring their safety and protection," said Mr Mujtaba.
"But we succeeded in securing the conviction of the six out of seven accused," he added.
Asked about some defence lawyers' statement that they would challenge the conviction of the six accused, the IGP said everybody has the right to go to the higher court.
"The case has to be fought in the court, not in the streets. If needed, we will also move the high court against the acquittal of one accused," the IGP said.