Start tomcat services using authbind this will allow user to start ports less than 1024 we do not need to redirect or iptables.
apt-get install authbind -y
To install Authbind software
chmod -R 755 /etc/authbind
group should be user group.
chown -Rh root:group /etc/authbind
After that run the below commands
cd /etc/authbind/byuid
As an example lets imagne user id is 2000 you can use your user id number
echo '0.0.0.0/0:1,1023' > 2000
That file should be own by user and group.
chown : 2000
chmod 700 2000
Add the below line in tomcat startup file $CATALINA_BASE/startup.sh
export JAVA_OPTS="$JAVA_OPTS -Djava.net.preferIPv4Stack=true"
For Starting tomcat using Authbind service startup.sh
Comment the below line
#$CATALINA_HOME/bin/startup.sh
Add This End as the end of the file
AUTHBIND_COMMAND="/usr/bin/authbind --deep /bin/bash -c "
$AUTHBIND_COMMAND $CATALINA_HOME/bin/startup.sh
now you should be able to start tomcat services as user with less that 1024 ports.