For the purposes of Section 68 of the Income-tax Act, 1961, which deals with unexplained cash credits in the assessee's books of account, the term "previous year" refers to the assessee's opted previous year under Section 3(1)(b), which is the twelve-month period ending on the date chosen by the assessee.

1. - At the instance of the Commissioner of Income-tax the Income-tax Appellate Tribunal, Delhi Bench " C ", has referred the following question for our opinion ;

"Whether, on the facts and in the circumstances of the case and in view of the provisions of Section 68 of the Income-tax Act, 1961, the Tribunal was right in law in deleting the cash credit of Rs. 20,000 in the books of account of the assessee on April 7, 1961, from his total income for the assessment year 1962-63 ? "

2. The circumstances which have given rise to the question aforesaid, briefly, stated are these: Lakshman Swaroop Gupta is the proprietor of M/s. Lakshman Swaroop Gupta & Bros., Bharatpur (hereinafter called " the assessee"), who deals in motor parts, electrical goods, miscellaneous articles, tyres and tubes. In the course of assessment proceedings for the assessment years 1961-62 (the previous year being April 16, 1960, to April 15, 1961) the Income-tax Officer found a cash credit entry in the sum of Rs. 20,000 dated April 7, 1961, in the name of Smt. Satyavati Devi, the wife of the assessee. The assessee could not explain the entry satisfactorily and the amount of Rs. 20,000 was added to the assessee's total income as income from other sources for the assessment year 1961-62 and subjected to tax. An appeal was taken before the Appellate Assistant Commissioner and it was contended on behalf of the assessee that the amount had been included in the computation of total income under the head "Other sources" and the previous year should have been the financial year and as the amount of Rs. 20,000 appeared in his books of account on April 7, 1961, if at all taxable, it should fall for consideration in the assessment year 1962-63 and not in the assessment year 1961-1962. The Appellate-Assistant Commissioner accepted the assessee's contention and deleted the said amount of Rs. 20,000 from the computation of the income-tax for the assessment year 1961-62 directing the Income-tax Officer to consider this amount in the assessment year 1962-63 after considering all the evidence. The department rest contended with the decision.

3. In the assessment proceedings for the year 1962-1963 it was contended on behalf of the assessee that the amount of Rs. 20,000 was received by his wife from her mother after the death of her grand-father at Bareilly and an old panchnama, which was contemporaneously prepared, was produced. But the document was dated April 10, 1961, duly attested by an Oath Commissioner. The Income-tax Officer disbelieved the explanation of the assessee and treated the amount of Rs. 20,000 as income from undisclosed sources of the assessee and added the same as the assessee's income from "Other sources". Feeling aggrieved, the assessee preferred an appeal before the Appellate Assistant Commissioner and pleaded that, in view of Section 68 of the Income-tax Act, 1961, the amount was not liable to tax in the assessment year 1962-63. The Commissioner did not accept the contention. Dissatisfied, the assessee preferred an appeal before the Appellate Tribunal and contended that as the cash credit entry did not relate to the previous year beginning on April 16, 1961, and ending on April 15, 1962, corresponding to the assessment year 1962-63, it could not be added as the assessee's income from "other sources" for the assessment year 1962-63. The revenue's contention was that the assessee should be deemed to have acquiesced when he pleaded for its consideration for the assessment year 1962-63 in the assessment proceedings for 1961-62. It was also urged that an anomalous position would result if this amount was excluded because it could not be considered in the assessment year 1961-62 and it cannot be included in the assessment year 1962-63. The Tribunal rejected the contention of the revenue on the ground that the illegality could not be cured by the waiver of the assessee. The Tribunal found that the accounting period of the assessee for which books were main