Division of property (land) bought together.

I had bought piece of agriculture land with my father in law in a small town. The purchase was done in year 2011. we both share 1/2 part in this piece of land. I live in New Delhi and never had any direct control over this piece of land. It was all in good faith. My father in law is now ILL and now we do not want to keep this land. I wishes to sell it and use the proceeds for something else. I am asking my brother in law (who says that he hold power of attorney on behalf of my father in law) to either a) sell the land or b) buy my share or c) divide the land so that we can independently sell our share. As he is not willing to do any deal, whereas he says that land partition had been done( which was not discussed with me) and he says that the my part of land is separate, where as we don't hold any government record of partition of land,and now he had built a room on the land (which he says is his part). furthermore overlooking to the dispute he raised , i requested him to sell or purchase my part but he is not willing to do anything, whereas now when i personally went into market to sell my part, people says that it is joint property and they ask me about the partition papers, I do not have any original deed of the land with me as it is with my father in law. can you please suggest me the easiest way as now my brother in law is against me regarding the sale. need your help Thanks Vikas