S. 124: Jurisdiction of Assessing Officer-The jurisdictional Assessing Officer is justified in processing the return of income filed by the assessee based on his PAN database residential address. The assessee cannot challenge the jurisdiction of the AO before the Tribunal in view of the limitation period prescribed under section 124(3)(a)-Assessee did not update current address in PAN database, and notices for scrutiny were issued and served at PAN address; said service was valid and constituted proper service. [S. 124(3)(a), 143(2)]