Oh that? It was actually the first time Ranbir was meeting up with with his Medical friends --- He already knew the engineering ones.So he had a group on some messenger of the medical students -- and they knew each other because they saw each others dps.But since it was the first time he was meeting up with the medical kids and Sarthak -- who is supposed to be a medical student--- did not have a dp and had not messaged if he was coming or not -- So, when Anshuman introduced himself as Sarthak, they all relaxed. They had been waiting for him.But I obviously think that Ansh lied to calm the situation and not appear as an enemy.He was working in the club as a bouncer of some sorts and was fired --- When I saw him standing at the gate watching Ranbir and Rose, I recognized him then only.