Disposal of fathers property fto meet medical expeses of father

My father has got brain heamorrage on 14th August 2012. Since then he is in a vegetative state wherein he is unable to move. His rightside limbs are paralysed. Since he was unable to breath normally, tracheostomy was carried out to breath. He is being fed through abdomenal tube. Two nurses were appointed to take care of him on round the clock basis. Sofar we could able to manage expenses by all possible sources. Now sources are exhausted and finding difficulty to meet his expenses. My father got agriculture dry land cultivating coconuts in eleven acres. Yield of coconuts is not good enough and the income is negligible. The only source of income is a joint commercial property. The income from this joint property is also not enough to cater the medical expenses of my father. In order to meet expenses, we need to sell a portion of dry coconut land or a whole 11 acres land. This land is in my fathers name. But my fathers condition is not good. He cannot sign or talk even. He cannot able to give his consent. In this condition is it possible for us to sell the land. Please note my father got 3 sons and five daughters. All are married. Myself is eldest son. The second son is a doctor by professoon. Third son is working in a software company. I being a eldest son given financial support to father for the marriages of four of my sisters and his other needs. I was working in saudi arabia from the age of 22 to 50 years. Now I have returned back to india and got no income. Due to misunderstandings arosed between my mother and my wife, all my brothers and sisters are against me and are not supporting. Now whole of my fathers medical expenses are on me. I need to sell atleast a portion of land to support medical expenses of my father. I know I cannot sell my fathers land alone, but I desperately needs to sell. Pl advice, how can I sell the land,