Is it possible to have a taxi for 9 hours for four or six passengers, to take us to Ngong Ping 360?

Do you mean that your landing time is around 9pm?
If yes, it is possible to have a taxi. However, if you have too much luggage, it is better to take two taxis.

The fare is different according to the distance and area. If you can tell me about the specific location you will start off, I may give an estimated cost.

We are staying in Hong Kong after a cruise and would like to know if maxi taxis are available at the ferry terminal for 6 to 8 people to visit Ngong Ping over one day - say around 9 am arrival.

Generally, the taxi in HK can only take 5 passengers and you need to take two taxis. Which ferry terminal do you mean?