Use of mixed adsorbent (Borasus Flabellifer coir powder and Ragi Husk powder) for the removal of chromium (VI) from waste water has been investigated in a batch mode process wherein influences of parameters like initial Cr (VI) concentration (20-60 mg/L), pH (1-3) and mixed adsorbent dosage (10-14 g/L) on Cr (VI) adsorption were tested by adopting both Box-Behnken Design (BBD) in response surface methodology and Feed Forward Artificial Neural Network (ANN). Optimum conditions for maximum removal of Cr (VI) from waste water of 20 mg/L have been analyzed by both the models, viz, mixed adsorbent dosage (12.3099 g/L in BBD and 12.1928 g/L in ANN), pH (1.6162 in BBD and 2.0912 in ANN) and initial Cr (VI) concentration (20.0261 mg/L in BBD and 20 mg/L in ANN). An ANN model was also developed in which 6 neurons were used in the hidden layer. The SEM and EDS photographs have indicated the surface morphology of mixed adsorbent and confirmation of metal ions adsorption.