According to this you'll have to try
System.out.println( "\\u" + Integer.toHexString('க' | 0x10000).substring(1) );
but it will only work on Unicode up to 3.0. If you want to get more values, just create a loop, e.g.
String foo = "கா";
for (int i = 0; i < foo.length(); i++)
System.out.println( "\\u" + Integer.toHexString(foo.charAt(i) | 0x10000).substring(1));
which produces
\u0b95
\u0bbe
If you want to have them in one line, change System.out.println()
to System.out.print()
and add System.out.print("\n")
in the end.