I'm assuming you're streaming to Twitch: If you mean lag as in it seems they're seeing your footage ~20-30 seconds behind (so their reactions in chat come in far later than what they're reacting to), that's normal and there's no real way around it. If they're seeing choppiness/it's pausing constantly for them, and OBS is not showing frame drops, that usually means that your bitrate is set too high; while Twitch allows 3500kbps streams, they do not transcode secondary qualities for non-partner channels (there's no "Source/High/Medium/Low" dropdown in the player), and as such people can only watch the Source version of your stream; for a lot of people, they can't manage a consistent 3500kbps, which causes hitching. Around here we usually recommend adjusting your total bitrate to be in the 2000-2500 range; for 720p30 content, that can be very good quality, and most people won't have trouble pulling that down from the server.