Given the complex band structures near the Fermi level in topological materials, multicarrier transport behavior is commonly observed. Multicarrier (multiband) model fitting is therefore widely used to extract carrier mobilities and densities from magnetotransport measurements. While two-carrier (two-band) and three-carrier systems have been extensively reported, experimental realizations of four-carrier transport remain rare. Bulk Ni_3In_2S_2, a topological kagome metal, has been reported as a compensated two-carrier system. Here, we successfully synthesized Ni_3In_2S_2 nanoflakes via chemical vapor transport and observed evidence for four-carrier transport in the measured nanoflake device. At low temperatures, the measured nanoflake device exhibits a field-dependent Hall resistivity with two low-field kinks and a high-field slope change in the positive-field branch, accompanied by an almost linear magnetoresistance. These features are consistently captured by a four-carrier transport model. Our results expand the landscape of multicarrier materials and provide a platform for exploring complex multicarrier transport and the potential origins of linear magnetoresistance.