local Pants = script.Pants
local Shirt = script.Shirt

local GroupID = 6763603 -- Group id here

script.Parent.ClickDetector.MouseClick:connect(function(Player)
    if not Player:IsInGroup(GroupID) then return end
    if Player:GetRankInGroup(GroupID) < 50 then return end -- Where 50 is, is where the role id is
    local Character = Player.Character
    if Character == nil then return end

    -- Get new shirt
    local CharacterShirt = Character:findFirstChild("Shirt")
    if CharacterShirt then CharacterShirt:Destroy() end
    Shirt:Clone().Parent = Character

    -- Get new pants
    local CharacterPants = Character:findFirstChild("Pants")
    if CharacterPants then CharacterPants:Destroy() end
    Pants:Clone().Parent = Character
end)

If anyone can tell me how to add more than one that would be great, I tried several times but failed in doing so.

Thanks :)