Currently, we are running Symantec DLP 15 with Oracle 11g in two-tier installation and now want to upgrade Oracle to 12c. As per the Upgrade checklist for Oracle 11g which upgrade path, we should follow
https://support.symantec.com/en_US/article.TECH247450.html
1. Upgrade checklist for Oracle 11g SE1 or Oracle 11g SE on servers with 2 (or fewer) CPU sockets.
2. Upgrade checklist for Oracle 11g SE on servers with more than 2 CPU sockets on a two-tier installation