<p>This paper is the first-principles study based on primary data and focuses on the investigation conducted on optical properties of (La₂NiMn0₆) by doping the A-site, respectively, using dopants strontium (Sr) and europium (Eu), respectively. The calculations noted out are generated using density functional theory in combination with LDA + U. These studies are carried out using varying concentrations of Sr and Eu in LNMO (La_2-xSr_xNiMn0₆) (La_2-xEu_xNiMn0₆). The values of x lie between (0.1 and 0.3), taking the mechanical stability of the compound into consideration. Successful incorporation has been found to advance the parameters of dielectric function, absorption spectra, and refractive index of LNMO, respectively, when incorporated with Sr. With respect to Eu, results are generated in dielectric function, marking it as a success. The enhanced properties upon varying concentrations report advancement achieved in polarization and energy storage capabilities, respectively. These results generated also prove to be potential candidates in developing optoelectronic devices, respectively.</p><p>In addition, the study delineates the underlying mechanism behind the changing optical properties while observing the Density of States (DOS) and electronic band structures carefully. Final calculations are noted using Density Functional Theory, which resulted in the change of electronic distribution and band gap, which overall affects the materials optical responsivity when doped with Sr and Eu. It is pertinent to report that Sr doping tends to increase the transparency in the materials in the visible range of the spectrum, marking it more suitable for applications and devices requiring high optical clarity. Parallel to it, Eu doping is well known in the devices related to energy storage devices, respectively. The results will solve the problems related to the needs of modern-day society and innovations for future technological aspects.</p>