You cannot collect rent on any mortgaged property, even if you just purchased it.
You must still pay the 10% interest fee to the Bank immediately. If you choose to lift the mortgage later in the game, you will be required to pay the mortgage value plus another 10% interest to the Bank. Key Strategic Constraints buying a mortgaged property in monopoly
If a player goes bankrupt to you and turns over mortgaged properties, the same "immediate 10%" rule applies. You must pay the 10% fee right away, then decide whether to pay off the principal or wait (incurring the extra 10% later). You cannot collect rent on any mortgaged property,
When you acquire a mortgaged property through a trade or sale, you have two immediate options regarding the mortgage: Key Strategic Constraints If a player goes bankrupt
Before a player can sell or mortgage a property, they must first sell all houses and hotels in that color group back to the Bank at half price. Handling Bankruptcies
You cannot build houses or hotels on any property in a color group if even one property in that group remains mortgaged.