The orthoferrimanganites Nd0.65Sr0.35Fe xMn1-xO3 (x=0.1,0.3,0.6) have been investigated using XRD, MÖssbauer spectroscopy, magnetization and conductivity techniques. The XRD reflections exhibit single phase structure. The paramagnetic-superparamagnetic-magnetic transitions were observed from MÖssbauer spectra and magnetization measurements in the temperature range from the liquid nitrogen to the room temperature. The conductivity study of the x=0.1 and 0.3 show semiconducting behavior with more pronounced conductivity for the latter leading to an activation energy double that of the former. The effect of the Fe substitution on the electronic and magnetic properties was analyzed and discussed.