TDS under Section 195 at 20%

Yes, if TDS under Section 195 is deducted at the rate prescribed under the Income Tax Act / Finance Act, then applicable surcharge and Health & Education Cess also need to be added. Therefore, if the base rate is 20%, the effective rate will generally be 20.8% after adding 4% Health & Education Cess, assuming no surcharge is applicable. If surcharge is applicable, cess will be calculated on tax plus surcharge. However, if deduction is made at a beneficial DTAA rate, surcharge and cess are generally not added separately.