if there are enough funds in your account, your position will be converted into delivery.
otherwise, Your position would be squared off on the expiry date at the prevailing market price.
I dont know completely about delivery. In effect, You can take delivery of any commodity in the market except crude oil I guess.(taking delivery of 100 barrels of crude is impractical I guess coz there are no mini or mic lots in crude.)
If the moderators could kindly shed some light on delivery in commodities market I would really appreciate it.