getting in the Pakistan Air Force isnt easy, for one making through the initial selection will be a major challenge for you with them knowing you have given up your previous citizenship. remember there is a serious tussle going on with the west and Pakistan right now. they might reject you purely on the basis of having to avoid the addition background and security clearances. after all there are thousands that apply, so PAF is never short of applicants.
out of the thousands, around 100 make it to the academy. nearly half of which get washed out in the first year at the academy alone. less than 15% of the original course graduates from the academy. out of these around 70% make it fast jet training.
its a long shot, but just keep in mind what you have to give up in order to just be eligible to apply.
good luck