Yes, the site is mine. But I want to use that files for more than one website, because of that, i can not know the WP installation folder name. This is the problem.
And because of that, i need to check for users in both tables. The website owner may want the login from custom login form. So, i need to handle the login and check if wp is installed or not, to decide which login will be used.
Temporarily, I created a db record for wp installation folder, but trying to do this automatically.