2A = 4 (inside lower berths)
3A = 6-8 (side lower berths)
SL = 8-12 (side lower berths)
In all the above classes, 1 lower (or side lower) berth is used as seats instead of berths, 1 berth = 2 RAC seats.
These...
more... numbers and seat/berth locations are for normal ICF coaches, it may be different in the larger LHB coaches.
source :IRFCA