Claim that our property belongs to wakaf

My paternal grandfather purchased a land around 16-17 years ago and built a 2 storey private residence over it. He even owned his property card until his sad demise 2 years back. My grandmother suffered financially as she had to pay off her husband's debts and decided to sell of the 2nd storey for the same purpose. The interested buyer even paid the amount as he was a far relative with which my grandmother cleared off my grandfather's debts. Later when the process of property ownership transfer began, it turned out to he complicated and we came to know that there has been a wakaf entry somewhere due to which the property can't be transferred on my grandmother and eventually she can't transfer it to the buyer. We have been struggling over it for months now. Have no idea what to do. Can anyone share an opinion on this?