How is pitch related to frequency.? If there is a pitch for a fundamental frequency, will that pitch be same for harmonics?
For a single note (as compared to a chord) there is only one pitch.
The sound typically consists of a fundamental and some harmonics. For example, you play the open A string (note = "A2") on the guitar you will get 110Hz, 220Hz, 330Hz, 440 Hz, 550Hz, etc.
Pitch is mainly determined by the spacing of the harmonics. So if you were to hear the frequencies 220Hz, 330Hz, 440 Hz, 550Hz, etc. you would still perceive the pitch to be an "A2" (corresponding to 110Hz) despite there being no energy at 110Hz.
A different way to think about it is periodicity in the time domain. Pitch is determined by the repetition rate of the time domain waveform, provided the repetitions are "similar enough".