Ya could be but why then 60 seats will show up against GN RAC if at all those 6 out of 60 is included in (as per your calculation) 60 TOTAL RAC seats for this train.
The count will always be different and will look different.
If there are 60 GN RAC, then it will show RAC 60;
If it's RL RAC, then...
more... it will show RAC 6 against those tickets which are booked in RL Quota.
I dont find any logic behind SHOWING 60 RAC seats in GN Quota and then plucking out 6 seats for RL Quota.