Sync data in SQL Server 2014 with Oracle database12c
You have a few options:


Transactional replication: this has been around for quite some time
and works nicely within its narrowly defined scenario.
Unfortunately, the use of non-SQL Server subscribers is deprecated.
Change data capture + SSIS: this is the Microsoft recommended solution. It's a bit more involved than replication (to me anyway) but it's also more flexible. You can do some really powerful things with SSIS as the data mover, if you ever need it. Basic concepts described here with a detailed example here.
Oracle solutions: you can also do it from the other end. Oracle has similar capabilities as SQL Server including their GoldenGate software. However, I believe it's extra $$$ for license. I don't think you'll need to tread this path but calling it out for completeness.