Chemical reactions were used to create (In1-xCrx)2O3 powder with (x = 0, 2, 4, 6, 8 and 10 at.%), and an electron beam gun was used to evaporate thin films in a high vacuum. The impacts of Cr doping concentration on the structure and optics characteristics of the In2O3 layers were investigated. All Cr-doped In2O3 films had the cubic structure of In2O3 without secondary phases according to the X-ray diffraction findings. A study of the chemical makeup of each Cr-doped In2O3 compound revealed that they were all almost stoichiometric. To extract the optical characteristics and energy gap, a three-layer model simulated the experimental data of the spectroscopic ellipsometer. With increasing the Cr doping concentration, the optical band gap shifted the blue was seen. With increasing Cr content, the band gap in the (In1-xCrx)2O3 thin film was raised from 3.21 to 3.46 eV. Using the Murmann's exact equation, the refractive index and extinction coefficient that were obtained through spectroscopic ellipsometry could be utilized to fit the measured transmission data. As a function of Cr content, the change in structural parameters was be used to explain the change in the optical parameters. The (In1-xCrx)2O3 thin film are recommended for optoelectronic devices due to its tunability in the structural and optical properties.