Ranjan Gogoi, J.

1. The two appeals, at the instance of the revenue, seek to challenge the order dated 29.12.2005 passed by the learned Income Tax Appellate Tribunal, Guwahati Bench (hereinafter referred to as the Tribunal) by which the assessments of the respondent-assessee for the assessment years 1999-00 and 2000-01, respectively, have been set aside on the ground that the same are barred by limitation. The appeals have been admitted on the following substantial questions of law:

1. Whether on the facts and in the circumstances of the case, there was infraction of the provisions contained in Rule 11 of the Income Tax (Appellate Tribunal) Rules, 1963 and if so, as to whether the same has vitiated the order of the Tribunal dated 29.12.2005?

2. Whether on the facts and in the circumstances of the case, in a case where the return of income is furnished under Section 148 of the Income Tax Act, 1961, service of notice under Section 143(2) of the said Act beyond a period of 12 months from the end of the month in which the return was filed would render the re-assessment proceedings invalid?

Though the above questions framed have been sought to be reformulated by the appellants at the hearing we did not find any substantial difference in the questions as framed by the court and those suggested on behalf of the appellants. We, therefore, proceed to consider the appeals on the questions of law already framed, as noticed above.

2. The brief facts that will be required to be noticed for an effective adjudication of the issues arising in the two appeals may now be stated.

For the assessment years 1999-00 and 2000-01, on receipt of notices issued under Section 148 of the Income Tax Act; 1961 ('the Act'), return of income was filed by the assessee on 24.1.2003. On 5.2.2004 notices under Section 142(1) of the Act were issued to the assessee for production of the documents mentioned therein. It appears that on behalf of the assessee an elaborate reply was filed for each of the assessment years. The representative of the assessee was also heard by the Assessing Officer. Subsequently assessment orders under Section 143(3) of the Act were passed on 26.3.2004. The assessee unsuccessfully challenged the aforesaid assessment orders before the learned Commissioner of Income Tax and thereafter moved the learned Tribunal. The learned Tribunal recorded the finding that after returns were filed by the assessee on 24.1.2003 notices under Section142(1) of the Act were issued on 5.2.2004 and no notice under Section 143(2) of the Act was issued at all. Accordingly, the learned Tribunal thought it proper to arrive at the conclusion that the assessments in question stood barred by limitation.

3. Sri Bhuyan, learned Counsel for the appellant, has submitted that the ground on which the learned Tribunal has set aside the assessment orders was not specifically taken by the assessee in the appeal before the learned Tribunal. In this regard, the grounds urged by the assessee in the memorandum of appeal filed before the learned Tribunal, which were reproduced by the learned Tribunal in the impugned order, has been referred to by Sri Bhuyan. Sri Bhuyan has also placed before the court the provisions of Section 254 of the Act and Rule 11 of the Income Tax (Appellate Tribunal) Rules, 1963. Sri Bhuyan has argued that under the proviso to Rule 11 of the Rules it is incumbent on the Tribunal to give an opportunity to the affected party if any new ground of appeal is urged at the hearing. No such opportunity was afforded to the revenue in the present case. Sri Bhuyan, learned Counsel for the appellant, has also urged that though in the present case, admittedly, no notice under Section143(2) of the Act was served on the assessee, the same will not vitiate the assessment orders inasmuch as pursuant to the notice issued under Section 142(1) the assessee had placed elaborate written submissions before the Assessing Officer which are available on record. Sri Bhuyan has also s