Bulk dense ceramics are needed in many electronic applications instead of powder with grain in the nanometric range that is the prime objectives of the present research. In this paper, Ni0.5Cu0.2Cd0.3Fe2−xLaxO4 ceramics were prepared sintered at 900 °C from Sol–gel synthesized nanocrystalline ferrites. Sintering of nanocrystalline powders has been done to obtain dense ceramics which in turn affects the structural, electrical, dielectric and magnetic properties of these materials. Structural characterizations were performed by the X-ray diffraction (XRD) technique. XRD data were analyzed by the Rietveld Refinement method with the Fullprof suite programme. By the implementation of data, structures have been analyzed and it is observed goodness of fitting as well as different parameters which include crystallite size, cation distribution, crystal structure using Vesta, electron density and Maximum Entropy Map has been obtained for each of every set. Furthermore, densification, dielectric properties, initial permeability, ac conductivity, etc. have been done with La3+ substitution. The influence of La3+ substitution on the magnetic permeability curve of the sample was studied at room temperature. With the arisen frequency the real part of permeability remains almost constant and shows a better relative quality factor. Enhancement of initial permeability of dense ceramics was observed with the substitution of La3+. It is depicted that the dielectric loss tangent reduces remarkably with increasing La3+ content.