In host machine iptables is running and is blocking the port 5901. Kill all the vncserver desktop in the host machine and run the following command in the terminal. Type the password for the user when prompted.
sudo iptables -I INPUT 1 -p tcp --dport 5901 -j ACCEPT
The above command will add the port 5901 to iptables in accept mode. Now save the iptables and start thevncserver in host machine then try connecting it remotely.
Stop firewal or iptables service
#service iptables stop