Create table test(
y varchar2(50 char),
z clob
);

insert into test1 values('কেমন আছ তুমি','কেমন আছ তুমি');

insert into test1 values('你好','你好');

insert into test1 values('How are you','How are you');

insert into test1 values('I am fine','I am fine');

select y,vsize(y),z,LENGTHB(TO_CHAR(z)) from test1;