A thorough examination focused around  linear and non-linear regression of various kinetic models (Pseudo 1^st Order and Pseudo 2^nd Order), two parameter isotherm models (Freundlich, Langmuir, Tempkin, Duninin-Radushjevich and Hill) and three parameter isotherm models (Redlich-Peterson, Radke-Prausnitz, Koble-Corrigan, Sips and Toth) were analyzed to investigate different aspects of Cu(II) biosorption onto dead immobilized Rhizopus Arrhizus (DIRA). Batch sorption studies were made at 30±2 ºC and Optimum pH for Cu (II) biosorption on DIRA was 6.5. Coefficient of determination (R²) was utilized to demonstrate the integrity of the fit of a model. Sum of the square of the errors (SSE), mean square error (MSE), root mean square error (RMSE), sum of the absolute error (SAE) and average relative error (ARE) were likewise utilized. Non-linear method found to be more proper technique for getting parameters. Based on R², SSE, MSE, RMSE, SAE and ARE among two parameters models Langmuir isotherm enumerated the experimental data best and among three parameters models Redlich-Peterson & Radke-Prausnitz isotherm models gave the best depiction of the work directed. Pseudo 2^nd order kinetic enumerated the biosorption of Cu⁺² using DIRA best.