Hi where can we change this word “Publish a Listing” of page title that appears only on browser tab.

Ideally via some SEO plugin, or via translation file.

Sir i have tried in theme.po file but still it remains same when we publish a new listing.

Its not going to be theme string.

Then Sir where can i find the string in which file.

Core/Messages I would guess.

As per there is no such folder such as Messages under Core please suggest sir it will be very helpful.

Osclass contains Core, Messages and Backoffice transaltions.

Sir i have changed the word "Publish a Listing" in oc-content/languages/ all files but still at the browser section still appears like in the image given below.

You have not or you use seo plugin.

Thank you for your help sir its resolved now.

When you edit po extensions with a normal editor, it can cause problems. You should use PO editor for this.

Does not make sense to edit PO files manually when Osclass use MO file.
You can handle translations from backoffice too.