Fraud against property within brothers

Hello sir, my father has sold his share of land to the party recently which was 14.5 kanals. unfortunately he had given 3 kanals to his big brother in 2010. his elder brother has registry of the 3 kanals but intekaal was not documented after that so that was the reason it was on my father's name till we sold to the party. now my father's elder brother is saying give me the property you have bought. my father just bought a 13 marla plot which is costing us 13 lacs. my father gave us the other money and we two brothers bought some property. i want to mention here that my father sold his share for 12 lacs per 8 kanals (21 lacs 75k) which is all documented as registries. the intekaal has been done to the party we sold. my uncle now preparing a lawsuit against us so he can file it under ipc 420. my question is how can he claim the money and land which was just not documented under his name till that time. how can he put charges to my father. will court say that we have to give him the money according to our sale deed that was 12lacs. what are the consequences we have to face, any advice we be appreciable.