My brother was admitted to PTU and regretted his decision a lot in the first year. However, he wants to be financially strong enough to restart his education in a new college and pay the fees again. He continued studying at PTU and graduated in 2015.
Soon he landed a government job and he realized that college doesn't matter in the long run. What matters is your knowledge and ability to ace the interview. Choosing either college, GNDU or PTU, will offer similar opportunities as it is you who decides your prospects.
So rather than focusing on the ‘better college’, become a better person and become a top ranker. As long as you are committed to hard work, all colleges will offer similar opportunities to you.