Yes, you can use the below script in a business rule triggering After creating a user. In the script, the $groupDN variable specifies the distinguished name (DN) of the group. For information on how to get an object DN, see https://www.adaxes.com/sdk/HowDoI.GetDnOfObject.
# Bind to the group
$groupDN = "CN=My Group,OU=Groups,DC=company,DC=com"
$group = $Context.BindToObjectByDN($groupDN)
# Initiate group membership update