We do have indigenous LPG supply, but it is not sufficient to meet local demand specially in peak winter season. I believe we import a significant percentage of overall LPG consumed in the country (will have to check, don't have the exact figures at hand).
The government has discouraged automotive LPG use to ensure that northern regions and rural areas continue to get whatever LPG supplies. Automotive margins are higher and if LPG is allowed in cars/taxis there will not be much LPG for domestic use where it is sold at a controlled/discounted price across the country. I believe the GoP (for once) has the correct policy in this respect, and hence we have to rule out LPG as an automotive fuel in Pakistan.