This is my first post on this forum, but a silent reader here and a regular viewer of the show.
On the basis of recent episodes and the promo,
Kuch din pehle we saw Sanskar warning Ragini on her cheap tricks of the Kitchen and that he had witnessed it. But seeing the promo it is sure that Sanskar ke warning ka uss par koi asar nahin hua and as we are shown the CD was fake and nothing was recorded on it .
But here Sanskar had to be a little more cautious, and that CD should have been real though he says that they cant be so cheap as her so that Ragini wouldnt be confident to throw Swara out of the mansion.
Because Ragini is so chaalaak and it is difficult to bring out her truth straightaway unless she confesses herself which is difficult as of now as her repentance for her deed is also fake or else she would have been revealed her truth and Swara's innocence at least to her father who showed immense trust in her.
So in short she has not only cheated Swara or Laksh but also her own family that includes her father and even her daadi. So IMO only recorded evidences would help in revealing Ragini or she has to be caught red hand and that would also happen only with the help of a well created drama..