Airport Hotel (sky rooms) offers discounts for PIA trainees. The rooms have been renovated recently. Find the hotel manager/marketing manager and bother them till you have the discounted room in your hand. Rate 2 years back was around 18,000 per month which is not bad. PTC is next door barely 2 mins walk.
Other option is live in airport hotel first week and meantime find out of city colleagues. Best bet for rent would be malir cantt there are many airline people there, you can get a reasonable portion for around 20-30k or a full flat in 40+. split it with 2 or 3 people and that will be it.
All the best