Seepage in RCC

Yes, but more information would be required.

Pl let me know what sort of additional information is required ? there is no pipeline passing near by , only suspect we have is Air conditioner in appartment exactly above my appartment , but when we checked , there was no sign of even drop of water.

It is possible that source of water leackage would be some where else , and we need to detect the same

Yes the tool is a saw cut a hole in the ceiling and look. I could be a water line or sanitary line with a leak in it from deterioration. If you don't the leak could be come a flood. The small hole that you need to cut is easy to patch compared the amount of ceiling that may come down if it get saturated.

Do you find traces of water after it rains?

or is it near a heat source, it could be a pipe sweating, cold water pipe with hot air causes condensation on the out side of pipe.

could be a statue of Mary stashed in your ceiling

I also had faced similar problem. I stay at 4th floor, I found there was seepage from drain pipe from 6th floor which passed through 5th floor wall then travelled horizontaly in 5th floor flooring and caused seepage in my 4th floor ceiling. After pipe was replaced the seepage has completely stopped. So you need to check not only floor above you but upto terrace.

The water could also travel a long way from the source before finally appearing at your ceiling. As ozzb says, you need to cut a hole & look and be prepared to track the leak back to it's origin.

more info: is it from above your head or below your knee level? Follow the seepage to its souce .. you might put food dye in the water supply to see if its from water pipe or rain . Check roof for any type of break, or crack , or missing broken shingles. Many times a crack up the roof will let water run underneath the shingles and come out perhaps 10 - 100 feet away. Use all weather tar repair sealant (ace hardware) to seal all cracks and all breaks anywhere in roof.. (be careful on roof use safety rope.)