The approach I am trying is to write a dynamic script that would generate mirror tables as in Oracle with similar data types in SQL server. Then again, write a dynamic script to insert records to SQL server. The challenge I see is incompatible data types. Has anyone come across similar situation? I am a sql developer but I can learn python if someone can share their similar work.
Have you tried the "SQL Server Import and Export Wizard" in SSMS?
i.e. if you create an empty SQL server database and right click on it in SSMS then one of the "tasks" menu options is "Import Data..." which starts up the "SQL Server Import and Export Wizard". This builds a once-off SSIS package .. which can be saved if you want to re-use.
There is a data source option for "Microsoft OLE DB Provider for Oracle". 
You might have a better Oracle OLE DB Provider available also to try.
The will require Oracle client software to be available.
I haven't actually tried this (Oracle to SQL*Server) so am not sure if reasonable or not.
How many tables, columns?
Oracle DB may also have Views, triggers, constraints, Indexes, Functions, Packages, sequence generators, synonyms.
What is the best way to migrate all data from Oracle 11.2 to SQL Server 2012?