S. 90 : Double taxation relief-Non-Resident-Royalty-Fees for Technical services-Rate of tax-Most favoured nation clause-Protocol-Agreement was signed on same day of signing of protocol-No requirement of separate Notification for implementing most favoured nation clause-Not justified in denying benefit of straight rate of tax at 10 Per Cent. as per DTAA-Additional charging of surcharge and education Cess-Not justified-DTAA-India-Portugal [S 90(1) 115A, Art, 12]