In our country (India) it is considered Sunnah to eat the trotters of the Qur‟baani animal ten days after the 10th Zil Hijjah?

Answer

The person has misunderstood the Hadith. It is not Sunnat to consume trotters 10 days or 15 days after the 10th. The purport of the Hadith is to state the permissibility of preserving Qur'baani meat. At one time it was forbidden to keep Qur'baani meat for longer than three days. All the meat had to be consumed within three days.

In the Hadith of Hadhrat Aishah (Radhiyallahu anhu) is mentioned the permission to keep Qur'baani meat after three days. In other words she referred to the cancellation of the early prohibition.