Deinstall Oracle 11g database

Go to location of 11g database setup :-

[oracle@sonu database]$ cd  /setup/linux_11gR1_database_1013/database

[oracle@sonu database]$ ./runInstaller -deinstall

open window >>>>>>

 Select OraDB11g_home1

after that 

Click on REMOVE button...

 Click on YES>>>>

Click on YES>>>>

Click on CLOSE Button....

After that remove base_directory(/11g)..