5 aircraft and 7 cabin layouts, from the 72-600 to the A330-200. Pick one for its seat map, the best seats and the seats to avoid.
There are seat maps for 5 Air Serbia aircraft here: the Airbus A319, the Airbus A320, the Airbus A330-200, the ATR 72-600 and the Embraer 195.
The Airbus A330-200, with 257 seats: 21 Business and 236 Economy in its main layout.
The Airbus A330-200, with 32" of seat pitch in Economy and seats 17.7" wide.