Hi Hamad,
It is good that you have posted here. Here are my thoughts: Generally for jobs, the start point would be connecting/ networking with your friends from Bachelors Degree as most/ all of them would be employed and it would be easier for them to get you in their firms as they know you personally and can vouch for you.
There are companies in Pakistan that do work specifically on post-tensioning like Izhar or other Bridge Construction Companies. I would suggest getting back to your friends first and if that doesn't work, scan through advertisements in newspaper. You can also connect with people here that are active to see if they have an opening in their office etc.
Thanks.