Trained in Your Jedi Arts (1 pip)
General Grievous
General Grievous gains Disengage and 1 dodge token. At the end of his activation he may perform an attack against each enemy unit at range 1 using the following weapon: Melee/Range 1: 1R 2b 1W Suppressive,  Versatile.

Grievous's pistol armament: Melee - Range 2 : 2 Black 2 White. Critical 1, Pierce 1, Versatile. (12 points).

Versatile means the weapon can be added to a melee dice pool, or can be used to shoot at a target at range, while you are engaged with another unit in melee.

If I were to use That command card. Could I during the Disengage extra attack at the end, use the pistol with it as well since he has Arsenal 2 and it has Versatile?

You don't have to disengage to get the extra attack. So it would also be possible to additionally use one of your lightsabers against a melee target.

29 minutes ago, Petforces said:

If  I were to use That command card. Could I durin  g the Disengage extra attack at the end, use the pistol with it as well since he has Arsenal 2 and it has Versatile  ? 

You don’t get to use Arsenal because the intent is clearly that the weapon on the card is the only one Grievous has access to for the attacks. That’s how the devs played it on the livestream.

18 minutes ago, nashjaee said:

You don’t get to use Arsenal because the intent is clearly that the weapon on the card is the only one Grievous has access to for the attacks. That’s how the devs played it on the livestream

This is a rules forum, not a "that may be the intent" forum. There's nothing in the rules or the card text that prohibits you from using Arsenal 2 on that attack. If you can provide a text saying otherwise, I stand corrected, but so far, for me, the rules are clear on what you can do.

Anyway, I agree with you that it is not intended to work that way, but that doesn't mean that a player doesn't get to use it. Tbh it probably means that there is a future rule that we don't know about yet or they will have to do an errata on that card (or the small third probability: it was intended to work that way but they forgot to use it during the stream).

Another possibility is that an effect that says "make an attack using [X] weapon" inherently means you can only use that weapon as it's the only option. It's worth asking them I suppose.

34 minutes ago, nashjaee said:

Another possibility is that an effect that says "make an attack using [X] weapon" inherently means you can only use that weapon as it's the only option. It's worth asking them I suppose.

I think that's the key. Arsenal X says:
" When choosing weapons during the “Form Attack Pool” step of an attack, each mini in a unit that has the arsenal x keyword can choose a number of its weapons equal to the value of x."
But in this case you don't get to choose weapons, the command card is choosing the weapon for you, so I guess you don't get the chance to use Arsenal.
Maybe that's a way to see it with the actual rules, but I agree that a clarification from the designers would be good.