Is there any way, by which I can execute PL/SQL commands in Raspberry Pi?
I know that MySQL, and SQLite doesn't support PL/SQL, so are there any other means by which I can execute PL/SQL commands in RPi?
PL/SQL is a proprietary language owned by Oracle Corp. This is why you only see support for it in commercial RDBMS's such as Oracle itself and IBM DB2. The latter presumably pay giant licensing fees for the privilege.
Any of the above could release an ARMv7 version that might work on the Pi 2, but it seems they have not.
So you are out of luck.