Ohhh I just watched epi 77 where towards the end Rhiddima tells Kabir she will go get the box at night from Chachi and hangs up call. Kabir angrily throws his phone against the wall and said "If Ragini showed such smartness in trying to find the proof then Vansh would be in jail". That one sentence told me a lot..
To me I am looking at it as one of two angles I had from start:
1) Ragini was /is agent with Kabir sent to take down Vansh and get evidence about him by being in place as fiancee but Vansh found out & ended engagement; or
2) Ragini was/is lover of Kabir and together wanted to take down Vansh but something happened to her
These are my two longstanding theories, the third newer one is
3) Anu had something to do with Ragini's disappearance & Kabir is unaware of this. Seeing how Anu dispatched of Mrs Dzouza and goodness knows who else so ruthlessly makes me wonder if she got rid of Ragini...perhaps she wants no DIL to take her place in Kabir's heart. If I think about it Rhidfu was engaged to Kabir 1st and that would make her her real son's ex-fianacee but instead Rhiddu is her stepson's wife now...either way Anu would be connected to Rhiddu.. and if Anu & Kabir want RaiSinhgania kingdom they would want no legal heir coming along should RiAnsh truly unite and consumate relationship in the long run?
For me this is 1st time Kabir has indirectly revealed he knows more about Ragini than we have been told as viewers other than being hell bent on getting Rhiddima to get Vansh to tell her what happened to Ragini. I do not believe Vansh killed Ragini...either she is alive & coming into plot in due course or a back story will be shown about her that tells what happened to her & Rhiddima will uncover razz.
Thats my thoughts anyway, would be interested in your views.