The quantum chromodynamics (QCD) like framework of the renormalized quark-meson (RQM) model has been used to draw the phase diagram in the \(\mu - T\) plane and map the critical fluctuations around the critical end point (CEP). The RQM model parameters are on-shell renormalized after proper treatment of the quark one-loop vacuum fluctuation in the extended mean field approximation (e-MFA). The contours, of constant quark number susceptibility ratio to the free quark gas susceptibility, have been drawn and the RQM model results are compared with those of the QM model where vacuum fluctiation are ignored in the mean field approximation (MFA).