Purchased a chaal room year ago, now patpedhi asking for their claim o

We had purchased one chaal room in thane Maharashtra, during then it was rented by previous owner by taking high deposit. At the time of execution of agreement and 80% payment, we requested previous owner to return deposit and handover room. But even after 6months, he didn't do that, hence from balance payable amt, we adjusted the deposit amt and took the handover. Also, electricity and property tax changed in our name. Now after a year, one patpedhi is claiming that he had given mortgage loan to previous owner and now they will sell the property. Also they have old chain of documents with them. No information we were having regard this loan, also at no where the patpedhi has mentioned of their charge in the property. My query of the above situation: 1.whether patpedhi can give mortgage loan on basis of chain documents?? 2.while giving, they don't gave to register such loans against property online on Maharashtra documents registration site?? 3.we have outrightly purchased property,