@manii . I am sorry the question is not directed towards me but I thought maybe I could add a few lines.
Your father is entitled to import any car, any model less than 5 years old from Japan. Since he lives in Japan it is more wise if he gifts the car to you or any other Adult in your immediate family i.e. Sibblings, mother.
The procedure is quite straight forward. All he has to do is a) buy the car b) get the documents attested from the Pak High Commission in Japan. Documents must have car registration book, invoice, copy of his passport, an earning certificate and a gift undertaking. The later two can be downloaded from www.cbr.gov.pk.
Once the car has been shipped from Japan to Islamabad. He needs to send you the above documents + Bill of Lading which the shipping company provides.
And finally once the car arrives at Islamabad Dry Port you go there with the documents plus consignees ID card, pay the duty and ride the car back home.
You may also need to get services of a clearing agent. I know a guy who does it in Islamabad I can provide you his number if you interested.
As far as the duty is concerned it really varies from car to car. For instance a 2 year old accord with 50% depreciation will be assessed a duty of about 5.5 lacs, duty on Vitz is about 1.5 lacs.