How we can show data list in Mozilla Firefox?

Hi Shalini,

Giving you an example of DataList:-

<apex:page >
<label>Choose a browser from this list:
<input list="browsers" name="myBrowser" /></label>
<datalist id="browsers">
<option value="Chrome"/>
<option value="Firefox"/>
<option value="Internet Explorer"/>
<option value="Opera"/>
<option value="Safari"/>
<option value="Microsoft Edge"/>
</datalist>
</apex:page>

If it still not working in your Mozilla than update the version of firefox, Older versions firefox doesn't support HTML5 Datalist .