The script gives money to players that are not in the same group?

The problem is that when you are on this:

for _,v in pairs(game.Players:GetChildren()) do
if v:IsInGroup(police) or v:IsInGroup(marcano) then
v.Wealth.Money.Value = v.Wealth.Money.Value + 100

That script checks if a player is inside any of those groups, so it gives it to everyone, you would have to check if v is in the same group as plr So I would do:

local marcano = 2959195
local police = 3003695
local point = script.Parent


point.Touched:connect(function(part)
    local plr =  game.Players:GetPlayerFromCharacter(part.Parent)
    print ('The capture point was touched')
    if plr then
        if plr:IsInGroup(police) or plr:IsInGroup(marcano) then
            print ('The player is in an accepted group')
            if plr:IsInGroup(police) then
                local PlrRank = "police"
            elseif plr:IsInGroup(marcano) then
                local PlrRank = "marcano"
            end
            for _,v in pairs(game.Players:GetChildren()) do
                if v:IsInGroup(police) then
                    local VRank = "police"
                elseif v:IsInGroup(marcano) then
                    local VRank = "marcano"
                end
                if PlrRank == VRank then
                    v.Wealth.Money.Value = v.Wealth.Money.Value + 100
                else
                    print ('The player is not in an accepted group!')
                end
            end
        end
    end
end)

Hope it helps!

EDIT:

Add the word local before PlrRank and VRank like I did above.

Right now, you are giving money to players in any group because if a or b then f() end means that f() will run if EITHER condition a or b is true; so, in your case, money is handed out to anyone who is in police and also to anyone in marcano:

if plr:IsInGroup(police) or plr:IsInGroup(marcano) then

One way to solve this would be the use of an IntValue to determine the owner group:

1. In the editor, add a new IntValue as a sibling to this script (make sure they have the same parent)

2. Call it GroupId

3. Assign the id of the owning group to GroupId

4. Then change your if line from above to:

if plr:IsInGroup(script.Parent.GroupId.Value) then

This will now only give money to the group whose id you have defined in GroupId :)