The deceased, Ramdhar (35) got married thrice and there was a land dispute between his son and two wives, Station Officer, Dharmendra Yadav said.
Ramadhar was sleeping when his son attacked him with a hammer. He succumbed to injuries before he could be rushed to community health centre, Yadav said.
The body has been sent for postmortem while a case has been registered against the minor son who is still at large, police said.
Teams have been constituted to nab the culprit, Yadav added.