Call it a coincidence, most Hindi films focus on haunted homes when it comes to horror genre. A Flat is no different. In fact, it brings back memories of various films, including Bhoot [was it shot in the same housing complex?] and also Chetan Anand's multi-starrer Kudrat. Of course, it wouldn't be right to compare A Flat with Bhoot or Kudrat or even Vaastu Shastra or 13-B or Phoonk/Phoonk 2 because the plotline of each is different, although you can't ignore the uncanny resemblance with the finale of Kudrat.
A horror films works if it scares the living daylights out of you, if it succeeds in giving you goose bumps at vital points of the narrative, but barring a scene or two in A Flat [I'd like to single out the elevator sequence involving Jimmy Shergill], you don't break into a cold sweat or bite your nails in anxiety. The writing is clearly the problem here, which follows the beaten path in its post-interval portions.
A spate of unexpected events jolts Rahul [Jimmy Shergill] as soon as he lands from U.S. to pacify his lost love Preeti [Kaveri Jha]. First, the mysterious death of his dad [Sachin Khedekar], when he visits the flat, followed by the baffling disappearance of Preeti… and now Rahul finds himself trapped in his own flat, completely cut off from the world. The only companion he has is a ghost.