Nautanki Saala! was a thoroughly enjoyable movie, from beginning to end. The first half is hilarious and the audience was laughing uncontrollably. The second half becomes a little more serious, but the story of the three main characters is artfully interwoven throughout. The dialog is witty and the acting was superb -- I was particularly impressed with the lead actor, Ayushmann Khurrana, whose range of expression and detail to the nuances of his character was on full display. Kunaal Roy Kapur was lovable and is comical with his goofy, aloof look. Finally, Pooja Salvi starts a little slow but grows into her role progressively and delivers a powerful flourish at the end.
In short: watch the movie, you will not be disappointed. You will identify with the characters, you will laugh at their banter, and you will appreciate the creativity and imagination of the storyline.
P.S. This is the kind of movie you would want to watch with your partner or your friends, since some of the "romantic" scenes are not conducive to parent-child watching.