Install .php url is redirected to <host>:/installer/installer/install.php and returned 404

I installed nginx, php and my-sql on ubuntu.
I downloaded the gibbon tar.gz and extracted the contents to /var/www/html
When I run /index.php it is redirected to :/installer/installer/install.php and gives 404 code.
Please help.

Even If I visit installer/install.php it goes to installer/installer/install.php and gives 404

Hello anirudh, this double installer issue is odd, and not something we have seen before. All of the hosting I do is with Apache (call me old fashioned, but it works!), but I do know that @UrkoM has experience configuring nginx for use with Gibbon. Perhaps he might be able to add something to this discussion…