seniority of runnning staff after decatagorisation in alternate cadre

Submitted by AMOD on Sat, 01/02/2014 - 14:54

if a goods guard 4500-9000+30% decatagorised and get alternate post in O.S-II in scale mentioning 5500-9000,now after merging of scale

5500-9000 and 5000-8000 as gp-4200,where his seniority should be fixed whether with head clerk or with o.sII IF different seniority is being maintained of head clerk and o.sII.and pls tell me by which rule.