Yoginder Sharma Mamgai, who was on a morning walk, was waylaid by the accused, who snatched his gold chain at gunpoint, they said.
When he resisted, one of the the miscreants took out a pistol and threatened him not to raise an alarm.
However, when some of the locals rushed to the spot to help Mamgai, they fired in ther air to scare them and fled from the spot, police said.
A case has been registered in this regard, they added.