In this work, the context is doped Rare earth elements on the structural, optical and magnetic properties of the cobalt ferrite nanoparticles using sol-gel synthesis by calcinating at 500oC for 4 hours in air. Rietveld assessment of XRD data validated the formation of a single phase cubic spinal configuration for all formations coupled with magnetic properties and were investigated. SEM has been used to study the surface morphology of the compounds. FTIR and Raman spectra confirmed the structure with the appearance of standard modes. The Rare Earth replacement in CoFe2O4 ferrites has intense impact on magnetic properties. Hysteresis loops showed the saturation magnetisation values were increased/decreased from 55emu/gm to 25 emu/gm by inserting the Rare Earth (RE) material in the Rare Earth CoFe2O4 ferrite samples. Magnetic hysteresis data show that the coercive force is depleted with change in Zr, Sm Gd composition but the net magnetisation of the samples are not interrelated with dopant level.