You have the following options
a)Option 1: if you have details of your uncle's debt free properties you can share it with margadarsi and ask them to settle their dues by disposing of your uncle's property.
b) Option 2: You as a guarantor based on notice issued to you by margadarsi can also take an attachment order from court and attach all of your uncle's properties and sell them off and pay margadarsi.
b) Option 3: As a guarantor, you will be eligible to a full refund of monies along with interest that you pay to Margadarsi for the loan availed by your uncle. The reason is once you make the payment to margadarsi as a guarantor, by virtue of law, you will be replacing margadarsi as a secured creditor.
c) Since you are now a secured creditor to your uncle, you are entitled to attach all of your uncle's properties(mortgaged properties, mortgage free properties) etc and claim your dues with compound interest at the rate of 24% per annum from your uncle.
d) from law perspective, there will be no applicability of law of limitation. your uncle will be bound to pay you money with full interest of 24% per annum from the date it became due to margadarsi.
Hope this helps.