My Mother in Law (74yrs of age) harrassed by her son and daughter in law

My Mother in Law was harassed by her son and daughter in law in Jamshedpur, Jharkhand. She was confined and locked inside a room with no food, water and medicines and was constantly subject to physical torture. Even Covid vaccine was not administered. Thereafter, one day when her son and his wife had gone out for work, she fled to her daughter’s house in Kolkata for shelter with the help of a NGO. Her son and his wife have forcefully taken away all her belongings and assets, jewellery, Mobile Phone, money, Voter Card and Aadhar Card etc. Now she wants to file and FIR at Kolkata, WB against her son residing at Jamshedpur, JH. The local PS at kolkata is not taking FIR against her son stating its not in their jurisdiction/ state. How can she file FIR against her son at Jsr/JH being here at her daughters place in Kolkata,WB. She don't want to return to her son as she is too shocked from the torture receive. My Father in law has passed away a few years ago. How can she reclaim her property from her son for a healthy life.