Log on to your oracle server, and type
cd $ORACLE_HOME/OPatch
./opatch lsinventory -oh /full/path/to/oracle_home -details > /home/oracle/inventory_details.log
The top lines of the generated file will reveal what's installed in your ORACLE_HOME:
cat /home/oracle/inventory_Details.log | more
Result:
Installed Top-level Products (2):
Oracle Database 12c 12.1.0.2.0
Oracle Database Gateways 12.1.0.2.0
There are 2 products installed in this Oracle Home.
After that, more details about your installation is listed:
Installed Products (137):
Oracle Database Gateway for DRDA 12.1.0.2.0
Oracle Database Gateway for ODBC 12.1.0.2.0
Oracle Database Gateways 12.1.0.2.0