Wine shop license partnership issyey

Hi My father in law is not educated and has a younger brother who is educated and working as govt teacher in small town. When their father expired wine shop which was in their dad's name came to my father in law as he was the eldest son. But at that time his younger brother also made another agreement where it says that my Father in law and younger brothers wife both will be partners and future if anyone includes third party then it's contempt of this agreement and case can be filed. Also it says that this agreement is to be renewed every year. This was signed when my father in laws father expired 7 years back. The agreement also says that whatever profits come from the shop will be shared equally between my father in law and his brothers wife. Since father in law us not that educated and gullible his brother used to give only 10000 a month and keep the rest of the amount. Seeing for 7 years and finally when family convinced my father in law that they are taking him for a ride, he checked legally and with excise officer and finally decided to take ownership of the shop completely. When he checked on the partnership agreement all said it's not renewed and not valid including excise Dept officer and since the shop licenseis under father in law name they said he can go ahead and do as he wants. Based on this my father in law agreed to have another person take charge of the shop and run it and they also agreed to pay 75000 monthly. Once his younger brother came to know he now has come up with another agreement saying that there's a firm registered in both my father in law and his wife name and based on that this cannot be done. My father in law is not aware if this when it's done as he is claiming he doesn't remember signing anything like this before. Please advise how to proceed further on this. For 7 years his younger brother cheated him paying a paltry amount and now when he has realized that his brother was cheating him and planning to take control he is not allowing that to happen. Please advise.