Property in the name of twpo brother but their father still alive

Dear Sir/Madam, My sister's husband and his brother co own the property but their father is still alive. Now the issues is, my brother in law's brother want to sell his share to other people that my sister's in-law and husband asking no to do it. And in fact, my brother offer the money to buy the his brother's property but he is denying it and said he already sold the property to other party (which was against my brother in-law's consent) . So, my brother-in-law's father said he many not give any property to his other son but they are fighting for this. My sister's husband has 3 other sisters and they are supporting my brother in law. So, sir/madam my questions is - Can my brother-in-law father can take back the property which in the name of his of other son? What would be best way to resolve this dispute? My sister and her family is between brother's in law's brother and other party which want to buy the property and they are very disturbing. Please advise. Regards, Loken lokenbem@gmail.com