The deceased was identified as Ajit Yadav, an XI standard student in Nirmala college.
According to police, Ajit, his father Mahender and mother Lilavati were asleep in the house when his elder brother Sujit had at around 4.30 am stepped out to attend nature's call, closing the door.
Minutes later, two unidentified persons opened the doors, barged into the house and attacked Ajit and Lilavati with a sharp weapon, injuring them seriously, police said.
The duo were rushed to nearby hospital where Ajit was declared dead on admission while his mother was undergoing treatment, they said.
Police said that the motive behind the crime was not yet clear. The assailants had not tried to rob anything from the house.
Personal enmity might have led to the murder, police added.