We studied the dependence of carrier recombination pathways in nanoparticles of NiO on surface conditions. Two types of 0.6 nm short-range order clusters of NiO were prepared in reverse micelles of dodecyl benzene sulfonate. The steady-state absorption and time-resolved fluorescence measurements were done in order to investigate the photophysical properties of d-d in-gap transitions. The NiO nanoclusters and bulk steady-state optical absorption and emission properties are comparatively discussed from the prospective of Laporte's rules relaxation. The results of the time-resolved emission studies allowed us to develop the phenomenological model of the in-gap carrier recombination in NiO clusters.