Harassment by son and daughter in law, can case be filed against them?

My son and daughter in law are harassing us. They are being guided/helped by mother and father of our daughter in law. He is serving away from home. When i/my wife go there to see them & our grand daughter they not only misbehave us but also our daughter in threatens us to suicide. When they come to us on leave, they repeat all these things here. Even our daughter in once called there parents who misbehaved cried on us. I have audio recording of all these and even mobile calls of our daughter in law with his parents in which they are misguiding her as well as abusing us. My question is that can we lodge a anticipated FIR in local police station regarding her threat of suicide, when they come here on leave. I am retired defence person and now doing 2nd job. We have our own house purchased by me from my own savings.