Qantas classic flight awards in business class are ‘U’ and economy are ‘X’.
The number of available seats will never correlate to the number of awards... it could be an empty cabin but zero awards.
The easiest way for the OP to check if there are awards available for them is to log in to the Qantas site and do a booking. Availability can depend on status, so à bonze may not have the same access as silver, gold or platinum.