How can i change the icon of up and down arrow and change the text in configuration text. As, icons are not displaying at my end.
For the icons:
The icons come from the theme css, and by default are characters from the Entypo font that is included with Telligent Community.
For the text:
This can be edited in the administration area. Search for the "Poll Embeddable Content Type" plugin, go to the Translation tab and you should then have the option to edit the text used:
(As this is in the Telligent 8.x forum, should point out that this answer applies to 9.x and above only - polls in 8.x are done differently)
Hope this helps,