Piezoelectirc effect

We know piezoelectirc effect of some spefic type of material like rochela salt, quartz. It is nothing but due to blow of impact these material produces electicity and if they are supplied with electricity then these material produces vibration. Now my question is that do you thing that the "Frequency of the vibration depend upon the thickness of the material?

The material will not vibrate simply because electricity is applied. You have to apply a varying voltage to the crystal to make it vibrate. The thickness is important to how much total displacement takes place (how loud the sound will be).

Ya, You have rightly said, but not clearly told whethere thickness have any effect on the frequency of the effect or not.

The frequency of the effect is a function of the frequency of the voltage applied, not a function of the thickness of the material.