S. 143(3) : Assessment-Powers-Tribunal remanding matter to Assessing Officer to consider whether certain receipts constitute fees for technical services-Assessing Officer treating receipts as royalty-Beyond scope of remand-Reimbursement of expenses for use of software-Not fees for technical service-DTAA-India-USA [S. S. 9(1)(vi), 9(1)(vii), art. 13(4)]