We report an excellent room temperature NH<sub>3sub> gas sensing performance using highly mesoporous nanoflakes of Ni-Co hydroxide/Oxide synthesised by facile and economical wet chemical method. The dynamic sensing of NiCo<sub>2sub>(OH)<sub>6sub>(NCH) and NiCo<sub>2sub>O<sub>4sub> (NCO) shows nearly 3 and 2 fold increase in sensitivity by varying NH<sub>3sub> concentrations demonstrating excellent sensitivity which is in accordance to Freundlich equation. The interesting behaviour of NCO being p–type material spectacles n-type gas sensing behaviour towards low ammonia concentration at RT. The anomalous sensing response is ascribed to transition of majority charge carriers due to surface reaction of chemisorbed oxygen ions and ammonia gas vapours.