Kirchof Law

Yes it is applicable for both ac & dc....

It's Kirchoff with a capital K and two f's.

Friend i also attended NTPC kcl kvl are applicable for both ac n dc what more questions you got doubt? I also want to clarify more.

Kirchhoff law is applied to AC & DC circuits provided that they have a relation as Current in the circuit is proportional to applied voltage.
That is V=Z*I; Where V is applied Voltage in volts to the circuit I is current in the circuit Z is a constant and is known as Impedance in AC circuit has its unit as Ohms if the circuit is DC then it is known as Resistance and also has it units in Ohms.
They are many circuits that they do not follow this relation specially in communication circuits and power Electronic circuits.
For example circuit having the Zenor diode or AC circuit having inductance with iron core, in witch Flux density is maintained as long as below 1.6(Kirchhoff law applied) and flux density above 1.6 kirchhoff law does not applied due to non linearity or saturation in iron core.