Annual increment

Sir,I received 3rd MACP in PB.2,9300-34800Nov-2015 and regular promotion in March-2016 in PB.3,15600-39100.Pay fixed for MACP in Nov-2015.For promotion pay is not fixed only pay of promotional post corresponding to 15600-39100 is given 77900 which is fixed in Jan-2016 is not in level10 on March so the next figure is 80000/- Annual increment granted on 1.7.2016.Local PAO objected by bringing the RuleFR.26 and telling after fixation 6 months is required.As per MACP Rule Pay will be fixed at the time of MACP and on actual promotion no fixation only difference grade or concerned pay will be given.Along with me some more persons got promotion in March-2016.For them PAO allowed annual increment and in my case only he postponed to 1.1.2017.Last increment I received on 1.7.2015.Can anybody say annual increment period 18 months.Rules should be same to all or not.Kindly understand MACP Rule and give suggestion