There is unfurnately no direct upgrade path.
You will need to upgrade to BE16 first, then to latest 20.x.
See this section in below Article:
Please refer the following Table while setting the value for Upgrade version Key.
X indicates BE versions that can be upgraded from
About licensing :
You cannot use BE2012 license on BE20.
You will need to renew maintenance or purchase new license.
Please reach out to your local Veritas reseller for the best possible solution.