The incident took place outside the ticket counter when Sanjay Meena, a 35-year-old resident of Dwarka in Delhi, was going to deposit the cash in the accounts department, police said.
"When Sanjay was going out of the ticket counter, three unidentified armed men suddenly threw chili powder into his eyes and shot him," a senior police officer said.
Later, they snatched a bag containing Rs 50,000 and fled, the officer said.
A case has been registered at Sahibabad police station and police launched a manhunt for the accused.