Sitemap Not Found on Wordpress Website

I am using Google XML Sitemap for the site but it’s not working as the sitemap not found on the website URL http://republicdayimages2016.co.in/sitemap_index.xml.

In sitemap plugin it shows a notification about Webserver Configuration which i did using WINSCP. I add the following rewrite rules in a .conf file and put this inside file in /var/www/ac.com/conf/nginx/ directory.

“rewrite ^/sitemap(-+([a-zA-Z0-9_-]+))?.xml$ “/index.php?xml_sitemap=params=$2” last; rewrite ^/sitemap(-+([a-zA-Z0-9_-]+))?.xml.gz$ “/index.php?xml_sitemap=params=$2;zip=true” last; rewrite ^/sitemap(-+([a-zA-Z0-9_-]+))?.html$ “/index.php?xml_sitemap=params=$2;html=true” last; rewrite ^/sitemap(-+([a-zA-Z0-9_-]+))?.html.gz$ “/index.php?xml_sitemap=params=$2;html=true;zip=true” last;”

But still it’s not working. Help Needed. Thanks in advance