Now that we know Milsi and Neev are definitely leaving for Pune, looks like all the drama will unfold there. It also looks like Neev is not the killer but the one who is trying to protect Milsi from the killer. The fact that he is defenceless (considering he is having fake bullets in his revolver), indicates that he is going to get killed in the process of saving Milsi. Here are a couple of possibilities.
Scenario 1:
Prachi follows Milsi and Neev to save Milsi from danger. She witnesses Neev trying to kill Milsi and killes him instead (maybe she pushes him off the cliff of something). She gets arrested and inorder to save her Milsi lies that she is insane and she lands up in the mental asylum giving Amrita company
(I sure hope the creatives dont tread this path).
Scenario 2: (My preferred one)
Ranbir volunteers to follow Milsi inorder to ensure his safety. After he leaves Prachi still follows Milsi because she feels she needs to be close to Milsi , remembering the panditji's words that she willl be Milsi's shield. There she witnesses Ranbir and Neev shoot each other. While Ranbir is safe because he was shot with fake bullets, Neev dies. Both Mi and Chi are grateful to Ranbir for saving Milsi's life although they feel bad that Neev met a sad end. Having won their trust Ranbir then goes about his mission to destroy Milsi. He also befriends Soumya and pretends to love her. Prachi slowly gets suspicious of Ranbir's activities and realises he is the villian. Milsi does not believe her and this creates misunderstanding between them. At the end of this track Ranbir usurps Milsi wealth and Michi end up in the chawl. Yes, my favourite chawl track.