this my theory on the raaz , here goes
we know that bani's mom and jai were friends so may be when bani's mom was pregnant with bani she had come to mumbai for a visit at that point of time jai is involved with roshni and the two of them went for a dinner at that hotel(one which sahil's and other's engagement is suppose to take place ) on park road and got terribly drunk and after that went through park road and were met with a terible accident in which bani's mom who was walking on the road lost her child and jai and roshni seeing themselves in big trouble(also feeling sorry for bani's mom) over drunken driving and killing(of the baby) replaced the dead child with bani an orphan at the hospital and so now at the present they r afraid of the past being revealed to bani.
what do u ppl think about my theory plzz reply also plzz post ur theories 😆