Old settlement pending shows in the deed the old owner died.

Sir I am planning to buy a property from a couple (husband and wife). They buy the property from his (husband) elder brother and wife on 1989 November. They brought it from (elder brother) their uncle on 1989 April. When I read the deed I find that His elder brother not paid an amount of RS 2000/- to his uncle in old deed who died just after the deal. He added this debt in new deed also which we had now in hand , and he took RS 3500/- from his brother out of total RS 5500/- both agreed. Uncle himself not married and so no children. Uncle had one brother and two sisters They all died due to more ages but his brother son alive I heard. The property owner and his property given brother and other two brothers and one sister alive but one brother died due to age. My question is the mentioned uncle died and how can I settle the debt to him and write a new deed for me and took a bank loan with the same. I don't want any debt before I buy the property. Can the owner himself settle it as what he is saying ?. I not settle the total of 30 lakh yet but write and agreement with him in 1 lakh advance. Please give an immediate reply.