You are trying to install SEP 14.3 RU3 Linux agent on RedHat Enterprise Linux 6.7, agent installation ends with "No packages found that need update" output.
[root@#### Downloads]# ./LinuxInstaller
Running ./installagent.sh (PWD /root/Downloads/inst73erCk; version 2.2.4.46)
Configuring Repo file /etc/yum.repos.d/sdcss.repo for Symantec Agent for Linux (SEPM) ..
Refreshing repo cache and testing connection..
No packages found that need update
sdcss_install.log in instXXXX folder that is created during install (but deleted later) shows following output:
04/04/22 14:01:04: Repo communication status = 0
https://linux-repo.us.securitycloud.symantec.com/sep_linux/14.3RU2/rhel6/x86_64/repodata/repomd.xml: [Errno 14] problem making ssl connection
Trying other mirror.
Error: No matching Packages to list
Error: No matching Packages to list
04/04/22 14:01:19: No available package version found for sdcss-scripts
04/04/22 14:01:19: No script package found that needs update
RedHat Enterprise Linux 6.7
TLS 1.2 connection is needed to connect to https://linux-repo.us.securitycloud.symantec.com.
Run following command to update nss and curl to the latest.
yum install nss curl