How much will it help?
Well there is no age restriction but the movie will enjoy the advantage of it only when more & more people are willing to watch it. Emraan Hashmi doesn't enjoy "family audience" support. It's only youngsters who would choose it as the subject won't appeal to the "Teenagers". So when the youth is the main audience, U or U/A or A doesn't really matter. Considering the bad box office status of the lead pair & Rajkummar Rao's lack of box office pull.... This is completely dependent on the goodwill of the music, the director's previous movies & that's about it.
This U would work only if family audience turn up.