Interesting show and a lot of possibilities about the mystery.
Just watched today's epi. The hotel staff confirms that she saw Neha with Rishi.. and the cctv footage proves that Neha is not hallucinating and Rishi is a real person.
So Kabir is lying. Right now i think the best possibility is that Kabir married Aditti for money and killed her off. Then saw Neha and is now out to prove that Neha is Aditti and get the cops and lawyer off his back. The lady who was talking about "pari" in the second episode was probably referring to Aditi and i think she is Aditti's in-law, not mother. That is why the lawyer seems doubtful that Aditti's death is not an accident cuz probably she has no blood-relative and was the sole owner of her assets.
Rishi could be someone that Kabir got involved to get Neha to the place where he wanted...away from the life she has known...away from friends and relatives who could confirm her identify. Its hard to believe that Neha has no relatives or at least friends who know her (in case she is an orphan). If Neha really is that isolated then it goes to suspect that she really might be Aditi who survived the accident but lost her memory.