The 33-year-old actor confirmed the news by sharing a picture from the hospital bed.
He captioned the snap as, "Yes, I broke a leg. Thank you @TheFarahKhan @Patralekhaa9 4 being d best support system & sorry @kritisanon & team couldn't finish the show#LipSing."
The actor, who was facing off against his 'Bareilly Ki Barfi' co-star Kriti Sanon in the show, has had two fractures in his left leg and has undergone a surgery.
Host Farah also shared a picture and jokingly said the actor took the phrase of 'Break a leg' a little too seriously.
"Break a leg' doesn't mean literally! My poor @rajkummar_rao fractures his ankle but retains his sense of humour on 'Lip Sing Battle'... Pic credit @patralekhaa," she wrote.
Meanwhile, on the professional front, Rao will next be seen in Rakeysh Omprakash Mehra's 'Fanney Khan' where he will star alongside Aishwarya Rai Bachchan and Anil Kapoor.