First one, he should definitely song "Jaane bhi de/gustakhi maaf Karna" from Hey Baby to Rachna! This song fits him and Rachna soo well! 😛 like the mistake he did to Rachna, so he is singing this song in college lol, imagine it.
So what other suggestions you guys have? And it doesn't ony have to be with Rachna, it could be anything else. It could be him singing something to Gunjan or Rachna's parents 😆 and if you want it could be anyone singing not just Vihaan.