I am using the City / Town option. However, county information is not available when I choose any province. When using information from provincial cities in Turkey availiable. No county. Is it a problem? How to add zone information.
Can you please check if there is any data in the civicrm_county table? It might be that you just have to add some records in there because it is not prepopulated.
Have you enabled the state/province field?
Scroll down and enable state/province instead of county
I've just checked the drupal demo(but these are standard civi settings) and after selecting Turkey as a country a range of options appear in state, nothing in county.