My mother in law's property is divided by common roof and wall. The next door is his elder brother.

My mother in law's property is divided by common roof and wall. The next door is his elder brother. This property was given to them by their father. Also she has written a will but it is one sided. The will states that my mother in law or his successors should get NOC for selling the property from his brother. His brother can buy the property for whatever rate it deems to be right for him also is stated in the will. The will also states that we can't demolish, gift, exchange without their permission. but they can do whatever they want with the property. Now his brother has transferred the property to his daughter. She is just offering us a very low rate with which we can’t get anything, but since my mother in law is no more, my husband and mother in law are the equal partners in the property. My husband doesn't want to sell the property but my father in law is pressurizing him to sell it to the daughter. Even she is dealing with her without my husband's knowledge. Is there any way we can stop this or can they do anything so that my husband doesn't get a share. In case is there any possibility that i can prevent the sale of property.