S. 153A : Assessment-Search-Third person-Loose sheets pertaining to earlier years were found in third party premises-No inference could be drawn against assessee qua relevant assessment year-Theory of extrapolation-Not applicable on mere theoretical or hypothetical basis-Natural justice-Failure to provide an opportunity of cross examination the witness which the Department relied on-Addition cannot be made-Amalgamation-Assessing Officer framing assessment separately in name of Amalgamated Company, in spite of furnishing information-Order bad in law. [S. 68, 69C, 132]