  The interplay between superconductivity and Eu$^{2+}$ magnetic ordering in
Eu(Fe$_{1-x}$Ir$_{x}$)$_{2}$As$_{2}$ is studied by means of electrical
transport and magnetic measurements. For the critically doped sample
Eu(Fe$_{0.86}$Ir$_{0.14}$)$_{2}$As$_{2}$, we witnessed two distinct transitions
: a superconducting transition below 22.6 K which is followed by a resistivity
reentrance caused by the ordering of the Eu$^{2+}$ moments. Further, the low
field magnetization measurements show a prominent diamagnetic signal due to
superconductivity which is remarkable in presence of a large moment
magnetically ordered system. The electronic structure for a 12.5% Ir doped
EuFe$_{1.75}$Ir$_{0.25}$As$_{2}$ is investigated along with the parent compound
EuFe$_{2}$As$_{2}$. As compared to EuFe$_{2}$As$_{2}$, the doped compound has
effectively lower value of density of states throughout the energy scale with
more extended bandwidth and stronger hybridization involving Ir. Shifting of
Fermi energy and change in band filling in EuFe$_{1.75}$Ir$_{0.25}$As$_{2}$
with respect to the pure compound indicate electron doping in the system.
