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Abhishek, I work frequently with non-English data, so I must insist in the answer : see, non-ocidental languages (as Japanese) have more characters than the "space" present in an English-only database, your program canīt do NONE about this, is a PHYSICAL thing... So, the DBA ** must ** recreate/convert this database, allowing more "space" for the extra characters required, if you are the programmer only you donīt have A THING to do about it...
1) Normal language (english) makes me a bit angry man. What's wrong with the other languages? Moreover Oracle supports most of them for ages
2) Post here
select * from nls_database_parameters where parameterlike '%CHARACTERSET%'