You can bring your spouse and children to New Zealand on your investor visa, but not other family members. They would have to qualify for a visa on their own. I'm not aware of any exceptions.
Who can come with me on a New Zealand immigrant investor visa?
I have a large of extended family of two brothers, my parents and my wife’s parents. We are all interested in relocating to New Zealand, but who is eligible to do so under the law? Are exceptions made if someone is not eligible?
In terms of extended family, nobody can be included in your application. The only people who can be included are your spouse/partner and children.
You can include your spouse and dependent child up to 24 years of age. The dependency (including age) is assessed at the time of the visa application. There are no exceptions to allow additional family members to be included. There is a parent retirement resident visa that can be used later after you have obtained residence without any conditions. This will allow parents to apply for residency based upon a $1 million investment for four years. Other requirements do apply, of course, so do discsuss with your licensed immigration adviser for New Zealand. For siblings, there are additional points available under the skilled migrant category. Or you may be able to assist with finding work to move initially under a work visa, such as the essential skills visa, or perhaps assist with the entrepreneur pathway. Remember that for your investor visa you can buy a business. That may be helpful in exploring options to assist your family.