Hmm well, the procedure is now the same for all provinces including federal territory for an ALL PAKISTAN licence issued by the Ministry of Interior. If someone has a provincial licence, to convert it to an ALL PAKISTAN one, they have to go to the ministry of interior.
Ok now the process. You must be aware that the ministry of interior has changed the arms licencing process from a manual one to a printed card one (similar to the digital driving licence in Islamabad). The booklets issued previously are no longer available (the hoarded stocks also finished this month) so I wont go into that process as its a bit different.
1) Write a letter to the secretary of interior requesting him to approve your request for grant of an arms licence
2) If approval is given, you will be issued with a demand note by the ministry (or just ask someone you know to get you a demand note which is the way most people do it). After the issuance of demand note, you have only 6 months to complete the rest of the stages.
3) Deposit Rs. 5000 challan with NPB.
4) Buy a gun from a licenced gun dealer. Get him to put the weapon number on your demand note with his stamp.
5) Go to the concerned DCO with the demand note to get his endorsement and stamp. For Islamabad, this is the DC Islamabad and here you also have to register the weapon with the arms branch in the Katcheri before the DC will sign.
6) Fill out the licence application form. Attach 2 photographs, copy of ID card, original challan form and original demand note. Submit the application at the ministry of interior's arms branch.
7) Now wait for 4-8 months for them to issue you with a card as there is a massive backlog.
Btw, please note that the Ministry is NOT issuing new demand notes ever since the Government was dissolved. So you have to wait till after elections and the policy of the new Government. If you are in a hurry, find some high-level contacts.
As far as the police is concerned, there is no issue provided you follow the laws.
See my detail post on this here:
Hope this helps