Dear Sir,
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Yes, buyer should deduct Tax @22.88% in each share of husband & wife.
Yes,Form 26QB is to be filled in by each buyer for unique buyer-seller combination for respective share. E.g. in case of one buyer and two sellers, two forms have to be filled in and for two buyers and two seller, four forms have to be filled in for respective property shares.
Form 15 CA & CB would be required only in case of remitting money outside India.