Hi rakibxl,
The only way is to register for an API username here http://www.geonames.org/export/web-services.html and then try to make a call to something like http://api.geonames.org/postalCodeSearch?country=COUNTRY_CODE&username=demo where COUNTRY_CODE is a variable.
Refer below link.
https://stackoverflow.com/questions/9118037/is-there-a-class-or-library-to-get-list-of-states-for-a-given-country
Or you have to create your own list for populating the Province and ProvinceCode.
Like below link.
https://stackoverflow.com/questions/18539149/how-to-create-select-list-for-country-and-states-province-in-mvc/18539308