Property and other assets

Dear Sir, My father in law died intestate & is survived by wife, and 2 married daughters. We got the property papers transferred in mother in law's name by giving R/Deed. Bank accounts are also transferred in her name with elder daugher as nominee, as she is incapable to operate the accounts. Monthly transaction details etc are also shared with her. What would be the rights of daughters in this case ? The mother in law is not mentally stable & suffers from Parkinsons & Dementia is under treatment & is partially blind. She insists on staying alone in her house. Other relatives brainwash her on not giving property etc to daughters after her death. She also threatens to raise false cases against daughters, while actually daughters have been looking after her since past 2 years sacrificing their own personal lives & family committments. How does the law protect the daughters on their being true Legal Heirs & also for any false case / statement being filed by her against daughters. Somebody advised us to shift her to an old age home for better security & health reasons as she is not a financial burden, & some advice us to file a statement in police in advance giving the situation details.