Chakra Activations at OIE are coded by Rann Goldrich, and their numbers have nothing to do with changing classically assigned chakras of the human body. There are 14 in all, numbered 0-13.
In a group session for 14 people, the same Chakra # activation will work on 14 individual chakras. Every chakra being activated may be different for each respective person’s body.
If you aren't sure which one is the correct one to choose, then let your intuition choose for you. First of all, none of these are bad for you, so there's no need for concern. On the light side, what's your favorite number? Which one sticks out the most? Which one is the ugliest? Which one do you keep clicking on? These are queues from your awareness. :)