The TPO rejected the Transactional Net Margin Method (TNMM), consistently accepted in the preceding six assessment years, without assigning any cogent reasons and adopted the residual “any other method” under Rule 10AB. The Tribunal held that though res judicata does not strictly apply to income-tax proceedings, consistency in approach is desirable unless there are valid reasons for deviation, particularly in transfer pricing matters. The TPO had neither demonstrated any statutory change nor furnished reasons for discarding TNMM as the most appropriate method. Merely pointing out alleged flaws in comparables or observing that the assessee operated as a commission agent did not justify rejection of TNMM. Rule 10AB can be invoked only where none of the prescribed methods are appropriate and requires benchmarking with same or similar uncontrolled transactions under similar circumstances. In the present case, the TPO failed to establish similarity of transactions used as comparables. The assessee’s PLI under TNMM (OP/VAE and Berry ratio) was significantly higher than the mean PLI of comparables and was further corroborated by independent benchmarking studies. The Tribunal rightly faulted the TPO’s approach. Applying the principle in Radhasoami Satsang v. CIT (1992) 193 ITR 321 (SC), the High Court held that no substantial question of law arose. (AY. 2016-17).