Income tax on fees for technical service abroad

Indian Resident company hires US based entity who provides legal / consultancy service for indian companys patent registration work in china. The payment for such service will be made in USA, to the US based entity. In such case withholding tax will be applicable since the same is covered under Fees for technical service as per section 9(1)(vii). Now, for DTAA provision, which DTAA has to be applicable, whether INDIA - US DTAA ? OR INDIA - CHINA DTAA?

Thanks in advance,