Rule 24 (ii)
"When total marks of more than one candidate are equal,
the one who gets more marks in viva voce is treated as higher in
merit. If marks in viva voce are also equal, the one who gets more
marks in compulsory subjects is treated as higher in merit. If marks
in compulsory subjects are also equal the one who is older in age
is treated as higher in merit."
Source
FEDERAL PUBLIC SERVICE COMMISSION
RULES FOR COMPETITIVE EXAMINATION (CSS), 2009
Islamabad, the 24th November, 2008