FTP not connecting with VE

You need to add rules in the IPtables to enable the FTP port.

Add the following lines in the /etc/sysconfig/iptables
-A VZ_INPUT -p tcp -m tcp --dport 8000:8250 -j ACCEPT
-A VZ_INPUT -p udp -m udp --dport 8000:8250 -j ACCEPT
-A VZ_INPUT -p tcp -m tcp --dport 21 -j ACCEPT
-A VZ_INPUT -p tcp -m tcp --dport 20 -j ACCEPT

service iptables restart

Here the ports 8000, 8250 are the passive ports.

I have done this fix in the Plesk VPS