Annual Increment from Job change from PSU to PSU

I have Joined from Coal India Limited (CIL) to Airport Authority of India(AAI) in Feb 2017. My Pay was protected by Airport Authority of India in 2018 as per Basic derived from Coal India on 7th Pay Revision. However I have not been granted annual increment for 2018 as they said not more than 6 month have served in AAI. However I represented that when pay protection was given my previous service was counted than only my basic was derived as per that . Had i joined in Apr 17 znd not in Feb 17 i would have taken Apr 17 Basic of Coal India and not of Feb 17 . Further as per DOPT office memorandum regarding Technical Resignation and Lien-consolidation guidelines dated 17 Aug 2016 , para 2.4 says pay protection , annual increment rule. As per that past service rendered by government servant is taken into account for reckoning of the minimum period of grant of annual increment in the new post/service/cadre in government under the provisions of FR 26 read with Rule 10 of CCS (RP) Rules ,2016. Please advise whether annual Increment should be granted to me as per above rule .