A man donated and made Waqf some land for a Musjid and Madrasah.

Answer

Once land has been consecrated as Waqf, it cannever ever be transformed into non-waqf land. You have not explained why the man is reclaiming the land, and what does he actually mean by reclaiming it. There could be two scenarios here: (1) He is dissatisfied with the administrators of the Waqf land for valid reasons, hence he wants to be the trustee and administrator of the land which he has made waqf.

(2) He has become avaricious and greed constrains him to reclaim the land for personal use/ benefit.

If No.2 is applicable, then it is absolutely haraam. Never ever will the Waqf status of the land be cancelled, and it will be haraam for him to repossess the land.

However, if No.1 applies, and he has valid reasons, his demand to become the trustee and administrate the land will be valid and permissible. Whether he is justified in demanding the land as explained in No.1, we cannot comment since you have not explained the circumstances and reasons for his action.

But do remember that once land has been made Waqf it cannot be de-waqfed or transformed into land of any other status.