Ranveer is a method actor and all his directors can vouch on this. For him, there are no half measures whether it is in pleasure or pain.
Apparently, in one of the sequences of LOOTERA he was supposed to be in pain. And the actor asked for a safety pin and repeatedly pierced himself while giving this particular shot. The director and the unit members were dead against it, but Ranveer's argument was that it is a really poignant scene and every stab of pain was enhancing his performance.