The actor was promoting his upcoming movie "Besharam" when a reporter at the event asked what did Katrina gift him on his birthday yesterday.
"There is a phrase in English 'Mind your own business'," Ranbir replied.
The "Barfi" star and Katrina recently made headlines when their pictures while holidaying together in Spain were published.
There were reports that the duo will go on a holiday again, but Ranbir chose to keep mum on this too.
"When pictures get published, you only inform... What should I say," he said.