Depends on time of day. If you're going in the lunch or dinner prime times (11:45am - 1:30pm, 5:30pm - 7pm), it can get pretty crowded and can have a long wait...there's more bar/single seating and 2-top seating both in and around the outer balcony than seatings for 6. The couches along the inside wall of the outside balcony can handle 6 - the indoor tables are more designed for 4, but they can add chairs to stretch to 6 - there's also a large central table inside with bar-chair seating that can handle large parties - or when crowded they can put a party of 6 and seat other parties with you as a shared table.
I visit Nomad every time I visit AK, but I often hit it in the late afternoon between the lunch and dinner rushes - or sometimes right at the end of the day when the park is closing earlier...when I'm there with a friend I can score seating for 2 much easier than larger parties...if it's crowded, I'll accept outdoor seating too to increase my chances. At most I've had some 5-10 minute waits. If I go solo, it's much easier to score a seat at the bar or central table with no wait.