This discussion clarifies the application of TDS under Section 194Q and TCS under Section 206C(1H). It explains that TDS is generally applicable even if TCS is collected under 206C(1H). However, TCS collection is not required if the buyer deducts TDS. The consensus is that it's preferable for the buyer to deduct TDS to avoid TCS.
Sec 194Q(5) - The provisions of this section shall not apply to a transaction on which, (a) tax is deductible under any of the provisions of the Act; And (b) tax is collectible under the provisions of sec 206C Other than Sec 206C(1H)
Extraction From Sec 206C(1H),
2nd proviso of sec 206C(1H) - the provisions of this sub-section shall not apply if the buyer is liable to deduct tax at source under any other provision of this Act on the goods purchased by him from the seller and has deducted such amount.
In conclusion, TDS is applicable even TCS is collected u/s 206C(1H) But TCS is not required to collect if TDS is deducted by the buyer. So better, the buyer has to deduct TDS.