Is it possible for a DC LDO to be able to take in AC and DC
It is a standard practice to make linear power supplies by rectifying AC into a reservoir capacitor and use that unregulated DC voltage to create regulated DC voltage.
However, with such a high input voltage, the regulator has to dissipate a lot of power as heat. So depending on which regulator IC package you have and how much current you would like to draw, it might or might not be possible depending on how much the regulator temperature goes up.
Use the formula provided by analogsystemsrf to calculate how large capacitance you need.