Debt recovery

hi, I want to ask about case relating to debt recovery i.e A huge amount of money taken by X not in lumpsum but regularly and signed on promisory note and had a registered document which is taken on his name and that document is signed by the MR.X and Surety(x's mom(z)) from MRS.X (Y) where the document is a blank one signed by them and took loa whenever they want and after that MR.X not paid single rupee of interest .Now MR&MRS.X got seperated but not yet divorced .So,what am i going to ask is whether MRS.X(Y) Can sue him and what are the legal consequences of it and if MR.X has nothing to pay can we sue Z as Z is surety of MR.X .So , what are the legal consequences?please i'm searching on this case ...thanks in advance