We report a search result for a light sterile neutrino oscillation with roughly 2200 live days of data in the RENO experiment. The search is performed by electron antineutrino ($overline{ u}_e$) disappearance taking place between six 2.8 GW$_{text{th}}$ reactors and two identical detectors located at 294 m (near) and 1383 m (far) from the center of reactor array. A spectral comparison between near and far detectors can explore reactor $overline{ u}_e$ oscillations to a light sterile neutrino. An observed spectral difference is found to be consistent with that of the three-flavor oscillation model. This yields limits on $sin^{2} 2theta_{14}$ in the $10^{-4} lesssim |Delta m_{41}^2| lesssim 0.5$ eV$^2$ region, free from reactor $overline{ u}_e$ flux and spectrum uncertainties. The RENO result provides the most stringent limits on sterile neutrino mixing at $|Delta m^2_{41}| lesssim 0.002$ eV$^2$ using the $overline{ u}_e$ disappearance channel.
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