Nin'Zar, the imp familiar, likes its cushy new assignment serving a Pact of the Chain Warlock. So, it wants to help its master as much as possible by using the Help action when its master casts Scorching Ray.
The spell description for Scorching Ray says:
You create three rays of fire and hurl them at targets within range. You can hurl them at one target or several.
According to the Help action:
You feint, distract the target, or in some other way team up to make your ally's attack more effective. If your ally attacks the target before your next turn, the first attack roll is made with advantage.
When someone makes multiple attacks, they are separate, sequential events that happen during the course of that player's turn. For instance, with Two-Weapon Fighting, a player makes an attack event then makes a bonus-action attack event. When a fighter uses their Extra Attack feature, the multiple attacks are again separate, sequential attack events.
However, since the duration for Scorching Ray is 'instantaneous', if you fire all three rays at one target, it can be argued that this would count as one attack event. Just like firing both barrels from a shotgun at the same time would be one attack event. If this is the case, then the Help action could give advantage to each of the to hit rolls.
Does Scorching Ray being fired at a single target count as one attack for the purpose of the Help action?