S. 92C : Transfer pricing-It is mandatory for the AO to determine the arm’s length price (ALP) of the international transactions by following one of the prescribed methods-He is not entitled to follow any other method or to resort to estimation-The failure to follow one of the prescribed methods makes the entire transfer pricing adjustment unsustainable in law-The legal infirmity cannot be cured by restoring the issue to the TPO-The TPO cannot be allowed another innings to rectify the mistake. [S. 254(1)]