JUDGMENT

SARKARIA, J.:- These appeals directed against a judgment of the High Court of Judicature at Gauhati raise a common question in regard to the interpretation and constitutional validity of sub-clause (a) of Cl. (26) of Section 10 of the Income-tax Act, 1961 (for short, called the 1961 Act). The appeals will be disposed of by a common judgment.

2. R. Takin Roy Rymbai (respondent in Civil Appeal 579 of 1975) belongs to Jaintia Scheduled Tribe and is a permanent resident of United Khasi-Jaintia Hills Autonomous District under the Sixth Schedule of the Constitution within the State of Meghalaya. He joined service under the Government of Assam in 1941. In the previous year relevant to the assessment year 1970-71, he was posed at Shillong as Secretary to the Government of Assam. The Assam Secretariat building and office, which constitute his place of work was within that quarter of the town which is included in Shillong Municipality and is not a part of the area described in Para 20 of the Sixth Schedule.

3. The Income-tax Officer took the view that the assessee s income from salary in the relevant year arose in the non-scheduled area and as such is not covered by the exemption provi