You’d want a csv file with all the IPs assigned to ASNs known to be part of entity (country code IL). There are various places you can find these types of things. Here’s a global IP repository with CSVs: https://github.com/sapics/ip-location-db (though by the looks of it you’ll need to open the file in an excel-like program, sort the country code column and delete everything that isn’t IL, otherwise you’ll block everything as they only offer global lists). You will also need to update this from time to time as ranges can shift, for a use case like yours I’d recommend annually.

QBittorrent shows the flags of the countries for the peers, though I don’t know how precise they are.