Without a controlled re-entry, there is no way to know exactly where it will land until it is completely plunged into the atmosphere.
Controlled re-entry plunges the object into the atmosphere at a specific point which allows easy calculations to place where the object will land with a greater degree of accuracy.
The reason we cannot calculate where a free falling object will land is because we really do not know exactly where the atmosphere ends and space starts. The accepted Karman line, at 62 miles above sea level, is the best approximation, but that is what it is, an approximation.