Ok I think I better update you guyz with authentic information.

PSO had been conducting interviews from 5th july in Karachi and interviewers in Karachi and Islamabad interviews were conducted on Skype.

this first(1st) interview lasted for 13 days till 18 july after that 2nd interview calls were made to selected candidates only.

on 26 July-total of 23 final candidates were interviewed by MD Yahya Mir Himself in Karachi PSO Head Office. Intervew was general which lasted for maximum of 3 minutes for each candidates.Candidates name,intro,university and FYP was asked in it,That's it.

on 27 july-interview was conducted for Islamabad and lahore on Skype.total of 18 final candidates were called in Islamabad Office.about Lahore office,I do not know the candidates.

source: I was interviewed by MD PSO in Karachi PSO HO on 26July and my friend's interview was on 27 in islamabad.
all were mechanical engineers.I am a NUST graduate.

On 20June,PM Nawaz sharif Put a ban on all recruitments in federal organisations and federal autonomous bodies and PSO comes under it too so,How would PSO hire new employees when a ban is in effect?
About the Ban,anybody can open google and write PM bans federal recruitment and you will get all newspapers link confirming it.
Don't doubt any technical aspect of this Ban because I was selected in SSGC but due to this ban,I have also been put on a hold so if OGDCL,SSGC has cancelled their appointments so how can PSO hires new employees?

kindly only senior and technical people are advised to reply