Error getting NCLOB cyrillic value

Question

This is my problem:

DECLARE
    my_clob NCLOB;
BEGIN
    FOR rec IN (
        SELECT CLOB_TEXT
        FROM MY_TABLE a
           WHERE CL_LANGUAGE = 'ru')
    LOOP
        my_clob := rec.CLOB_TEXT;
        DBMS_OUTPUT.PUT_LINE(my_clob);
    END LOOP;
END;

I try to put the data from the column CLOB_TEXT (NCLOB) into the variable my_clob(NCLOB).

That's fine... but the problem comes when the text from CLOB_TEXT is in cyrillic.

When I print my_clob, it is shown with ¿ in every character. Any solution?

The charset from database:

NLS_NCHAR_CHARACTERSET(AL16UTF16)
NLS_CHARACTERSET(WE8ISO8859P1)