Section 20 in The Bihar Forest Service Rules, 1953
20.
On the basis of the marks obtained at the written examination the Commission shall arrange for a viva-voce test of the candidates who have qualified at the written examination :Provided that in exceptional circumstances with the prior approval of the State Government, the Commission may, at its discretion, admit candidates of the Scheduled Castes and Scheduled Tribes to the viva voce test even though they may not have obtained the minimum marks at the written test prescribed under Rule 17.
