Flavor Changing Neutral Current (FCNC) couplings are strongly suppressed in top sector at tree level in the SM framework by GIM mechanism. While the FCNC processes involving the top quark can appear in models beyond the SM. We study to probe the top quark FCNC coupling via single top quark production in association Z boson and a jet at the Future Circle Collider- (FCC-ee) at the center-of-mass energy of 350 GeV. We investigate the final state of where the top quark decays to a charged lepton (muon or electron), neutrino and a b-jet and the Z boson decays into two charged leptons. Therefore, the final state consists of 3 charged leptons, missing energy and a b-jet. We perform the analysis in a model independent way using the effective Lagrangian approach. The obtained upper limits on the branching ratios are (with luminosity of ): for X-coupling and for K-coupling.
