Sell of Property in kolkata

I had a house in kolkata. I have 2 Brothers both of them died. Now their son and daughters ( daughters married and not leave in this house.) both of had to daughters and one son and one of my elder brothers wife living and other died. the portion which I m occupied is entire ground floor and owner ship is in my name and I am paying the taxes to KMC in my portion and entitled as owner in which I live for last 10 years. other portion of my house is my mother's name till date though she died in 80's. and the taxes are given by my nephews in the portion they occupied. the land is still in my mother's name. Electricity and water bill is also in my name. I want to sell my portion due to financial crisis. but my nephews and other relatives ie my elder brother son and daughter did not allow me to sell my portion nor they are ready to take the portion by giving me compensation. my only child is surviving from cronical NUROLOGIAL DISEASE IE MIOPATHY FROM LAST 2 YEARS AND UNDER TREATMENT IN GOVT HOSPITAL and required huge amount of medicine every month for entire life which I cannot effort to buy as I am a retired person from non govt job and now I have not so much income to buy all MEDICINES for my son. my son also can not do any work as his entire left side becomes immovable and detorats day by day. I had to sell my house at any cost as soon as possible to give medical treatment to my son. please help me ASAP. How can I sell my portion or what are the steps I required to sell my house.