brother-in-law possessed property unlawfully

My mother in law gifted my wife a villa/house. My brother in law also got another property from his father which he latter sold . My father in law died in 2012. But my brother in law continued to live in the house which belonged to my wife & promised to vacate the room soon.But after my mother in law's death he refused to vacate the room & went away to his new apartment by keeping the said room under lock &key & fully furnished.Now in the mean my time my wife transferred the property to me through a registered deed without any opposition. Now my question is that can I sell the house to third party? can my brother in law throw injunction to this transaction? what will I do about the room which he kept under lock & key?I am facing difficulty to sell my house as no one is accepting it with lock. what should i do?
It may be noted that my brother in law claimed 50% of his mother's property which was gifted to my wife by her mother through registered deed. Is it a valid claim?