EXACT TDS RATE FOR NRI FOR WHOM DTAA BENEFIT IS AVAILAED & PAN IS NOT AVAILABLE - Income Tax

Dear Sir, can somebody can guide the following: An NRI is covered by DTAA agreement. He is not having a PAN. Interest earned u/s 195 of IT Act . What is the TDS to be effected. whether 20% or as per DTAA rates or 30.90%(normal rate as per Section 195 as there is no clarifty, can some body guide on the issue. Thanks Mohan