Ref. No. 1011/41-176
In the name of Allah the most Gracious the most merciful
The answer to your question is as follows:
Prawn is Halal or Haram? It depends on whether the prawn lies under the category of fish or not. Some Islamic scholars – linguists say it is a kind of fish, thus it is Halal. Other scholars – zoologists regard it a kind of crab other than fish, and hence it is Haram. However, prawn being a fish is preferable. (Imdadul Fatawa 4/103, Fiqhi Maqalat 3/217)
And Allah knows best
Darul Ifta
Darul Uloom Waqf Deoband