refer from https://www.cyberciti.biz/faq/install-nginx-centos-rhel-6-server-rpm-using-yum-command/
cd /tmp
wget https://dl.fedoraproject.org/pub/epel/epel-release-latest-6.noarch.rpm
sudo yum install ./epel-release-latest-*.noarch.rpm
install nginx rpm repo
cd /tmp
wget http://nginx.org/packages/centos/6/noarch/RPMS/nginx-release-centos-6-0.el6.ngx.noarch.rpm
rpm -ivh nginx-release-centos-6-0.el6.ngx.noarch.rpm
install nginx
yum install nginx
chkconfig
chkconfig nginx on
service nginx status
service nginx stop
service nginx start