Tinting is illegal, still many people do it. A couple of rangers and police were parked when I was going home a few days ago, they stopped almost everyone with tinted windows and removed it immediately, they also checked the trunk of each car for some reason.
That's happening in Karachi. I just installed nets to for privacy, it works and none stops you. And if you see a checkpoint of cops, the best way is to slow down and switch on the cabin lights and let them have a look. This way you'll be free from being pulled. Easy and helps.