The incident occurred late last night when the victim Narasimha Reddy had brought some gold ornaments to sell them at a jewellery showroom, they said.
"Six unidentified persons hit him either with a rod or wooden log on his head, after which he fell unconscious. Then they took away the bag which contained the gold ornaments weighing three kg," Hyderabad Police Police Commissioner M Mahender Reddy, who reached the scene of crime, said.
"It seems the robbers had kept a watch on his movement. We have some clues and we will soon detect the case," Reddy said.