How far off the ball can offensive lineman be?

Answer 1

The length of the football defines the width of the neutral zone. When the referee places the ball on the ground, no player on either team (except the center on offense) may may line up with any part of their body inside the neutral zone. The neutral zone extends the entire width of the playing field.

Answer 2

Offensive linemen may be within 1 yard but not in advance of the ball prior to the snap. They must form a straight line perpendicular to the sidelines and comprise no less than 7 players.