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 (νe) disappearance taking place between six 2.8 GW th reactors and two identical detectors located at 294 m (near) and 1383 m (far) from the center of the reactor array. A spectral comparison between near and far detectors can explore reactor νe 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 22θ14 in the 10−4 ≲ | Δm412 | ≲ 0.5     eV2 region, free from reactor νe flux and spectrum uncertainties. The RENO result provides the most stringent limits on sterile neutrino mixing at | Δm412 | ≲ 0.002     eV2 using the νe disappearance channel.