Issue With Mother

Me and my husband staying with My mother in West Bengal. My mother wasted lac of rupees last year. All cash withdrew. When I come to know about same I asked where she used this money she doesn't have reply. She is also in touch with few people with whom she is talking even after we tried her to stop. Recently she threatens us that if u will try to stop me or ask questions about money, I will put case / FIR on your people that you people are doing mental harassment on me for the last few months. We have all bank detail of money she took from the bank in cash, all outgoing call detail. As she is senior citizen we can't leave her but staying with us is really tough but we need some legal help to save life. We have stopped all money to her except monthly required exp to her but we are not sure she will take a loan from the market to gamble things.