Comparing these two, i would say pec is much better than uiet in terms of lot of factors which includes placement . Pec has much better placements as compared to uiet as seen from the records. Also it is a very old college and has a great reputation among big companies. Apart from that there is a peaceful and aspiring atmosphere among students for studies . Of course facilities you ll get in PEC are much more better than UIET. So overall i think you should go for PEC .
Speaking about the University institute of Engineering and Technology, the placements are good for Computer Science and IT streams. The placements for Core streams are not good enough.
In PEC the placements for CS and Electronics department are excellent. For Civil stream L&T, Ramboll, Atkins, Maruti Suzuki and some structural consultancy visit the campus every year. PEC is a better college than UIET.