How to make claim on property when making a personal loan?

Hi! We are loaning a significant amount of money to a relative and wanted to know if there is any way to make a claim on their property without transferring title, or if we do transfer title, do we have to pay taxes? They currently have a tenant (not themselves) in the property they own. How do we go about getting claims to the property with them continuing to receive rent and be responsible for the upkeep of the property? We have already made a promissory note... should we add it as collateral without transferring the property?