A typical coil will have 2 pins, one will be for 12v feed, the other will be for ground via the ecu.
A coil pack like this will have 3 pins - one for 12v and the other two for ground via the ecu.
The way you'd find the right pins would be to measure resistance: pin1 to pin2, pin1 to pin3, and pin2 to pin3.
Two resistances would read the same, and the other would be the sum of the resistances.
For example on the MSD wasted spark pack I have: 1 to 2 is 0.6ohm, 1 to 3 is 1.2ohm, and 2 to 3 is 0.6ohm.
You have a problem in that you've got three pins.
It should be possible to find the common power feed to the coils as its the one wire that goes to both coils.
Once you have that you need to measure the resistance between the common and other two pins. And measure the resistance between the other pins.
There is a possability that the extra pin is used for misfire detection, but we can't discount the possability that these are coils with built-in igniters, which use a low current signal to drive them. The resistance measurements should show this.