Loan taken to settle Bank Loan default by Brother/Father (guarenter)

My younger brother had taken bank loan of Rs 5 lacs in 2008 for business purpose on the house for which my father was a guarantor. But according to him since his business did not do well, therefore he was unable to repay the bank loan and kept quiet about it. In 2009 when a bank sent a notice to my father (guarantor) stating the house property will be attached. To salvage this problem, he borrowed 5 lacs from me and settled a total amount of Rs. 5 lacs, plus Rs1.5 lacs interest from his own account with the bank. Till 2019, neither my brother nor my father made any effort to repay the money taken from me. He executed his will in Sep 2019, wherein he categorically mentioned that Rs. 5 lacs was taken from me to settle the bank loan taken by my brother. Subsequently, in March 2020 an amount of Rs 3 lacs was repaid by my father after a period of more than 10 years. My father passed away on 30 August 21. My brothers has now applied for probate, the partition of the property ( house & land) in their names which is currently under process. Needless to mention, my father has willed his self-acquired property to both his sons. How do i recover the balance capital and interest on the 5 lacs.