how take possession of own property

about 10 years before my Brother-in-Law purchased a plot of about 200 mtrs from the two different sellers 100mtr+ 100mtrs in Delhi on the basis of Power of Attorney, and the Power of Attorney could not be Registered that time.One of the seller was my younger brother. Later on my brother-in-law given that plot to his sister ( i.e my wife) but without any documentation as a free gift to make a house on that plot. Then in 2005 I built some rooms kitchen etc on my cost for residence purpose and started living there with my parents and two younger brothers. Electric Meter is also in name of my Brother-In-Law being a legal owner of the same. Later on due to nature of my job I shifted my family ( wife and kids ) another place on a rented house. My parents and brothers continued to live there. Two year before my youngest brother and parents also shifted to another place on rent after his marriage. The other brother from whom part of the plot was purchased continued to live there with his family. Now my brother who is living there do not want to go anywhere, saying that the plot / house is in his possession so he does not want to leave it. Kindly advise how we can proceed to take possession of the same? Legally what are the options for My Brother-In-Law or what option are left for me.