Can I use Mic to input Frequency Meter circuit?
Just connecting a microphone to the input of this circuit won't yield what you want.

First, microphone signals are very small, and this single-transistor amplifier has unpredictable gain, but not enough for a typical microphone to make a 5 V digital signal in any case.

Second, human voice contains a lot of harmonics.  The dominant frequency is often not even the fundamental.  This means there will be more zero crossings than what just a pure tone of the "same" frequency would produce.  You will not only have to amplify the microphone signal more, and more predictably, but you will also have to do some filtering to try to pick out the dominant frequency from the voice.