If $R= 0$ , $V= 0$ and $I=$ $max$ (i.e. charges are flowing at a huge rate), but when there is no potential difference applied to a circuit, charges don't flow. That means huge current flows when there is no resistance, consequently, the potential difference is $0$ but no current flows if no cell is added to the circuit i.e. the potential difference is $0$ again. How to explain this contradiction?
when there is no potential difference applied to a circuit, charges don't flow
This is not correct in general. This statement is valid only for a device with non-zero resistance. For an inductor, a capacitor, and a zero-resistance conductor it is not correct, charges can flow even with no potential difference.
For a capacitor current can flow with no voltage as long as the rate of change of the voltage is non-zero. For an inductor current can flow with no voltage as long as the rate of change of the current is zero. For a perfect conductor any current can flow with zero voltage.
So there is no contradiction. Ohm’s law is not a universal law. It is a specific rule that describes a small subset of all electrical devices.