The investigation of flavour-changing neutral current transitions(FCNC) involving the top quark are only possible with newtheoretical frameworks that extend the Standard Model(SM), given that these transitions are almost entirely suppressed within the SM. In this regard, examining these transitions with extended theories beyond the SM may provide significant insights into future experiments. To this end, we present a phenomological study about the anomalous FCNC transitions via tq. couplings with effective field theory. Here,...l.lb q, e + e-.e+...e+ l. lb qe -,... j jb q and e+ e-.e+.. e-.e+ j jb qe- processes are investigated for the CLIC at v s = 1.5TeV and 3TeV. Thus, we have calculated the constraints at 95% confidence level on the BR(t. q.). As a result, the obtained constraints are at least one order of magnitude better than the available experimental ones.