5 aircraft and 7 cabin layouts, from the DHC Dash 8-400 to the 737-900ER. Pick one for its seat map, the best seats and the seats to avoid.
There are seat maps for 5 SpiceJet aircraft here: the Boeing 737 MAX 8, the Boeing 737-700, the Boeing 737-800, the Boeing 737-900ER and the DHC Dash 8-400.
The Boeing 737-900ER, with 212 seats: 212 Economy in its main layout.
The Boeing 737 MAX 8, with 29" to 34" of seat pitch in Economy and seats 17" wide.