What: Does GoldenGate support extraction for Transparent Data Encrytion on SQL Server Database?
Answer: In Goldengate 11g and 12c, TDE is supported for Oracle Database but not for SQL Server database. There is no know workaround to Extract the data securely.
Refer to the Oracle Document on SQl server support – Non-supported objects and operations for SQL Server.
Refer to Metalink Document on how to setup replication for TDE data in Oracle – OGG How To Replicate Oracle TDE (Transparent Data Encryption) Data. (Doc ID 965745.1)