Partition of immoveable property aquired through partial HUF fund

X is father of A, B & C sons. X had got through partition from his siblings property1 originally purchased by X's father. Sons A & B are not well educated and runs a small family business FB1 that X inherited by paying off compensation to his siblings and them signing release of it. C is educated works separately, with 50% financial help of C the family re-constructed property1 so that it could generate rent. Further by mortgaging property1 and also taking funds from C, X purchased a vacant property2 in his name. After this purchase, with funds only from C the residential building was constructed where families of X,A, C & B lives. C has effectively funded about 70% of total market value of property2. Now the relationship between A,B, C & X is strained and is trending severance of joint relationship & partition of property. The question is about property2 & property1, how are these ought to be partitioned with the view of fair share among the family even it be unequal. Would contribution of C taken into consideration in the process, particularly for property2. Noting, all contributions made by C are on record bank transactions and no gift deed is executed for the contribution.