As you suggested i update my theme and plugins now Currency dropdown is working properly but other things are mess now on home page product with big images are appear also filter is not working now. is there any other changes i have to do?
If you have updated properly as described in the article and you haven't made any modifications then you should be fine.
Just clear your browser cache as the updated styles to be properly loaded.
You need to uninstall and then install the Ajax Filters plugin again as we made an improvement to the plugin that requires it to be uninstalled and installed again.
Please let me know if everything is working fine then.