This is not a spoiler but just a prediction... coz whenever they show Razia talking to Billo Rani they never show Billo rani's face.
I feel that Tanveer is the real Billo rani and she is the one who switched the recording to implicate Rashid... since she took the doll from the maid immediately after it came into her hand.
Do share if anyone else also feels the same way