If
Capacity = 24 KiB Associativity = 6 Line Size = 32 B
As far as I know:
$$Capacity = Associtivity * Line Size * Sets$$
so $24576 = 32 * 6 * Sets$
$Sets = 128 = 2^7$
thus 7 least significant bits are needed to identify set number.
Am I doing it correctly?