G004 Carnage

1. If a opposing character triggers ...THAT CAN RETURN TO ITS ORIGINAL SIZE to damage my friendly characters, can Carnage colossal retaliate against attacking opposing character or the Pym Pocket Tank?

053 Wolverine

2. If a opposing character triggers ...THAT CAN RETURN TO ITS ORIGINAL SIZE to damage my
X-Men friendly characters, can Wolverine use STAY AWAY FROM MY STUDENTS against attacking opposing character or the Pym Pocket Tank?

1. Yes - it's an attack. The colossal retaliation is made against Carnage who made the attack and not the tank that is getting placed.
2. Yes - Wolverine would make a close attack (provided that he's already adjacent or can move adjacent in that turn) on Carnage who made the attack, not the tank that is getting placed.

The Tank is the character doing the damage from its effect, and is after resolutions, so the damage is not from an attack at all. The attack made by the character places the Tank instead of doing normal damage.

Retaliators would only be able to choose the Tank. Stay Away won't be able to be used since the damage is not from an attack.

Thanks as always Lantern Jordan

If the tank is dealing the damage, does wolverine effect not trigger, because the tank isn't attacking?

Correct. As I pointed out in your incap thread: retaliators care about just damage. Students (cyclops has this power, too) requires it be damage from an attack.