Before you start please go to https://support.symantec.com/en_US/article.INFO3983.html to check your linux kernels support or not, it is not advised to upgrade your kernel for install sep.
install 32bit library before you start : (those are i386 libraries, cannot search by apt-cache search)
sudo apt-get install ia32-libs
sudo apt-get install libc6:i386 libx11-6:i386 libncurses5:i386 libstdc++6:i386
sudo apt-get install lib32ncurses5 lib32z1
upzip the install package :
chmod u+x install.sh
sudo ./install.sh -i
check SEP running :
ps -aux |grep -i symantec
reference link :