Position of guarantor under sarfaesi act

It all depends on the value of the property.  You have not given the value of property.  If it is possible for you to surrender the portion of your uncle, talk to the banker to take possession of that portion first and if it satisfies to appropriate the loan amount, the banker will not touch your portion.  If your father did not sign as guarantor of the loan, he can maintain a civil suit.  However, the rule of estoppel will cause trouble because your father must have been alert and objected to giving the house as security in the beginning itself.  Therefore the best approach would be to approach the banker talk to him to wait till the partition suit comes to logical conclusion in civil court or file an interim application in Civil court to partition the property to such an extent in favour of your uncle that would satisfy the outstanding debt.  And keep the bank informed that such an IA is pending in civil court as soon as the Civil court allows the application, the bank would be ready to take possession of that part of property which the Civil court releases in the name of your uncle.

Or if you have money you can purchase that which is sold by banker yourself and possess the part of your uncle legally.  That means you will negotiate with bank saying, "you enter into private treaty with us, you possess the portion that belongs to my uncle and sell it to us".  There is a provision for private treaty under Enforcement of Security Interest Rules, 2002.