If a emplacement trooper has an aim from target array or spotter and is used in fire support, can that aim be used in that attack?

I don't think so.

RRG, Page 13, under Aim:

"During an attack, a unit can spend one or more aim tokens..." Fire Support is not an attack, and I didn't see anything under the Fire Support rules that would specifically allow it.

RRG, Page 16, under Attack, Step 4:

"b. Reroll Dice. The attacker can resolve any abilities that allow the attacker to reroll attack dice."

I'm not sure if that's the intended functionality, but rules as written, it doesn't look like it is allowed.

11 hours ago, Bolcavage said:

If a emplacement trooper has an aim from target array or spotter and is used in fire support, can that aim be used in that attack?

No, because that emplacement isn't the attacker, he's just adding its weapon to the attack pool.

If you are not attacking, e.g. a firesupport unit, you may not spend any tokens. Only the unit who is attacking, the activating unit, may spend tokens. If they are in range of the firesupport unit and are clone troopers, they can use their tokens.

36 minutes ago, Cleto0 said:

If you are not attacking, e.g. a firesupport unit, you may not spend any tokens. Only the unit who is attacking, the activating unit, may spend tokens. If they are in range of the firesupport unit and are clone troopers, they can use their tokens.

Not exactly, the fire supporting unit does not require line of sight whereas the units that share tokens do.

25 minutes ago, syrath said:

Not exactly, the fire supporting unit does not require line of sight whereas the units that share tokens do.

yeah...? I was saying you use the clone tokens

17 hours ago, Cleto0 said:

yeah...? I was saying you use the clone tokens

I know I just wanted to clarify that , although in most cases if you are in range that you can fire support you can use the token of the other unit if it is a clone unit it is possible that if the clone unit has an aim token but not in line of sight of the attacking unit it could still fire support but not share it's aim because fire support does not require line of sight but token sharing does, it is a fringe case but worth mentioning

Pg. 39 under fire support -During the “Form Attack Pool” step of a friendly unit’s ranged attack, each mini in a unit with the fire support keyword may contribute an eligible weapon to the attack pool if that mini has line of sight to any mini in the defending unit.

2 clone trooper units at range 1 can use each others aim tokens even if one unit does not have line of sight of the defender but must have line of sight to use fire support.