Changing the NLS_CHARACTERSET to AL32UTF8 / UTF8

Changing the NLS_CHARACTERSET to AL32UTF8 / UTF8 (Unicode) in 8i, 9i , 10g and 11g (Doc ID 260192.1)
Note 788156.1 AL32UTF8 / UTF8 (Unicode) Database Character Set Implications
What languages are supported in an Unicode (UTF8/AL32UTF8) database? (Doc ID 1051824.6)

From SR

your existing database has a lot of LOSSY data that needs to be fixed.
But this can be fixed after moving to the new character set also .
( Path: you can export data, truncate table, convert characterset and then import data back into tables in new characterset).

But the problem here, you have a lot of LOSSY data. Both using fromchar=WE8ISO8859P1, tochar=WE8ISO8859P1 as well as fromchar=WE8ISO8859P1, tochar=AL32UTF8.

We shall see if there is an intermediate way to do this and bringdown lossy data.
Please provide below details:

1. Please run Csscan FROMCHAR=<WE8ISO8859P1> TOCHAR=<WE8MSWIN1252> and upload the csscan results.
2.
SELECT DUMP(COUNTRY_REMARK, 1016) FROM DW.TB_COM02190_DIM_GEOGRAPHY
where rowid='AACfPpABEAAADDqABV';
SELECT DUMP(SUPPLIER_NAME_CITY_CODE, 1016) FROM DW.BUF_SRC_DLV_MET_SUPP_PLNT_LK_1
where rowid='AACfPpABEAAADDqABV';
3.

select distinct(nls_charset_name(charsetid)) CHARACTERSET,
decode(type#, 1, decode(charsetform, 1, 'VARCHAR2', 2, 'NVARCHAR2','UNKNOWN'),
9, decode(charsetform, 1, 'VARCHAR', 2, 'NCHAR VARYING', 'UNKNOWN'),
96, decode(charsetform, 1, 'CHAR', 2, 'NCHAR', 'UNKNOWN'),
8, decode(charsetform, 1, 'LONG', 'UNKNOWN'),
112, decode(charsetform, 1, 'CLOB', 2, 'NCLOB', 'UNKNOWN')) TYPES_USED_IN
from sys.col$ where charsetform in (1,2) and type# in (1, 8, 9, 96, 112)
order by CHARACTERSET, TYPES_USED_IN