Oracle search problem with Georgian symbols

I have table with unicode data like 'საქართველო'.

When I execute this statement ... `

select * from table t 
where t.column = 'საქართველო';

... it returns no data/value.

Whereas if I create a function

create or replace function my_fnc (p_column in varchar2) 
  return sys_refcursor
is
  v_result is sys_refcursor;
begin
  open v_result for 
      select * from table t where t.column = p_column;
  return v_result;
end my_fnc;

it returns values.

Can you help me in this case?

Try explicitly casting your string as UNICODE:

where t.column = N'საქართველო'