How to fix a leaking concrete ceiling?
Presuming the place is built right or something close to normal &amp; expected. You would drill a small hole (drinking straw or pencil sized) in the dripping area of the ceiling so an Endoscope Camera could be inserted to catch the leak in action. This would be repeated probably just 2 more times until the leaking pipe is found.

When drilling the hole you'd want a bucket underneath to catch any puddled water up there or just have towels on the floor around a bucket &amp; insert a short bent piece of wire to direct the water down into the bucket.

Then, you rip out the entire ceiling &amp; permanently fix the pipe &amp; that means DO NOT use some screw-on piece of garbage that fake plumbers have been pushing for decades. The Landlord must be involved in all of this &amp; must be the one to have the above performed by a Real Professional Plumber.