Assuming you are a DV winner as you are in this forum and talking about the interview so most of the answers above are irrelevant. Get married before, and update your DS260 to add your spouse as well as submit one for him; also email KCC a copy of the marriage certificate (remember to include your case number on the email). This way he will get a DV derivative visa. The CO will want to see proof of a genuine relationship so make sure to bring it.
If you don't get married before, then you will have to petition for him as spouse once you get a green card. Longer and more onerous process. If he can oniy immigrate properly at the beginning of 2016, I'd say get him the DV visa, let him enter on that before it expires to activate his green card; he then has a year from that date to make the move permanent. Cost of an extra airfare but easier and possibly even cheaper in the long run to do it that way.
