on long it should get over 200km.! thats pretty standard, provided that
Your car is well tuned
Tyres are 12 size
Engine is strong
you have filled from a good pressure CNG.
AND you drive on light foot!!
getting 200km in full cylinder is not something impossible.For city driving, i feel no less than 135km, and from your location (Islamabad) that should be minimum as Isb is practically a highway driving most of time!!