Dado que no se encontra
Los contratos de compra/venta de inmuebles en La India sostienen que en los casos donde el vendedor tenga un familiar o grupo de personas familiares con interés de reclamo sobre la propiedad, se define como "vendedor que ratifica/confirma" aquel/aquellos quien (quienes) no ejecuta(n) la venta sino que asienta(n) su conformidad en el contrato, indicando que no tiene(n) ninguna objeción a que la venta se efectúe.

This aspect of confirming party comes mostly in cases of buying properties having several claimants and if the purchaser intends to purchase by settling with all the rival claimants at the time of purchase, other claimants would be shown as confirming parties. To avoid any sort of further litigation, when the purchaser has the knowledge that some other claimants also claiming some rights (either in courts or otherwise) over such property and he is willing to settle the disputes with scuh other cliamants can show them as confirming parties.
http://www.lawyersclubindia.com/forum/What-is-Confirming-Par...

Ratificar: glosario legal
Aprobar o confirmar actuaciones, palabras, opiniones, decisiones, decretos y reglamentos, dándolos por legales.
http://www.ramajudicial.pr/orientacion/glosario.pdf