1. Your Aunt is now the absolute owner of the said land which has been gifted to her by your father through a registered Deed of Gift,
2. Her oral promise to pay some thing to your father is on no consequence now,
3. Moreover, in Gift Deed, there will be no payment to be made otherwise, it will become Sale Deed,
4. Your father can not claim the said land under any circumestances,
5. If landowner 'A' sold the land to your father without disclosing about the court case and/or not being the absolute owner of the property and looses the case, then your father or Aunt can claim the sale proceed from him with interest, damage & cost.