Uninstall the oracle software

STEP-1) Before uninstalling the oracle software, make sure you have deleted the oracle databases and if any services running from the ORACLE_HOME

STEP-2)Below methods describes about uninstallation of oracle software:

1)Using uninstall tool with runInstaller
2)Using uninstall tool under Oracle home location
3)Manual uninstall

Method 1:
Remember when you install oracle software, you use runInstaller from the installation. Using same runInstaller can be used to uninstall oracle software as well.

Go to runInstaller location and run below statement
./runInstaller -deinstall -home /u01/app/oracle/product/12.1.0/dbhome_1/

Method 2:
Under ORACLE_HOME location, we get a deinstall utility that you can use to remove the oracle software.
cd $ORACLE_HOME/deinstall/deinstall

Method 3:
Sometimes ORACLE software installation gets corrupted and in such case, above deinstallation utilities will not help you to remove oracle software. Use below method to remove the oracle home using Linux commands.

Stop all the oracle databases as well as processes running from the ORACLE_HOME.

Delete ORACLE_HOME
*** please be cautious while you are  using rm -Rf command
cd $ORACLE_HOME
rm -Rf *
Delete ORACLE_BASE

cd $ORACLE_BASE
rm -Rf *
Remove oratab file
rm /etc/oratab