It is advisable to pay TDS amount by the buyer directly because as per income tax payment to be made should include TDS value so you must only make 99% payment to seller rest to government, if you make 80 lakh to seller it can be assumed that 80 lakh is 99% and then TDS will be calculated on it.
You need to file only 3 form 26QB as you have said there are only 3 buyers.
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