This is what I have made so far.
if players == 2 or 4 or 6 or 8 or 10 then -- The proccess end
I wish you wouldn't be so broad with what you need but this script will suffice I hope. What you need to do is get all the players, with getplayers method on game.Players, then you need to take out half of them and put them somewhere else to access half of all players later on.
local players = game.Players:GetPlayers() local halfPlayers = {} local num = 1 while num <= #players / 2 do wait() num = num + 1 table.insert(halfPlayers,players[num]) end --You can access half the players with the table 'halfPlayers'