False Case against my Uncle by his Wife

My uncle who is Muslim got married last year in Feb 2015.My uncle age is NRI and around 74 and he got married 2nd time after his first wife death. Bride is around 50 years. At the Time of Nikah Kazii asked the Bride brother that whether the Girl has been married first or not,the brother replied with YES.When Kazi asked about Talaaq Certificate it was not produced till yet. My uncle have asked before whether the Girl was married or not before ,but they told No,and on the day of Marriage it was found out that She was Married first with a Guy from Canada. After couple of weeks my uncle went to US for heart medical treatment and came back in December 2015 with a Pace Maker in Heart. Hewas heart broken by his wife cruel behavior in MP ,my uncle home town and she used to fight , demand money, speaking angirly and loudly , which has humiliate my uncle n his cousin family there.We had a meet with both side advocate for settlement and uncle can pay Rs1500 per month to her as per his financial status,as he is totally dependent on his Son. After returning from US and Uncle has filed for an Divorce and in return the Wife has filed an DV act case on my uncle and demanding 10 lakh or a flat in Surat. Wife is living with her mother who are staying in Small Chapra House and has another house too. Wife still doesn't have divorce paper from her previous husband which was some 20/years back. She has filed an false domestic violence case against my mother n my cousins. Can we file case on her in 506, 420, or a many advice on this case.