How long will it take to fully charge a capacitor in a series RC ciRCuit with a 6microfarad capacitor 2Kilohm resistor and 141 volt supply?

The time it takes to fully charge a capacitor depends on the capacitance and resistance of the circuit; the voltage is irrelevant. The equation you need is:

t = 5RC

where: t = time in seconds, R = resistance in ohms, and C = capacitance in farads.

So you should now be able to calculate the time for yourself, but remember to convert the resistance into ohms and the capacitance into farads before you insert the figures into the equation.