You are trying to seal moisture that is coming from the outside, from the inside. Ideally it should be done from the positive side (the side from which the moisture is coming)
But in some cases where positive side waterproofing is not possible due to inaccessibility, then you need to go for negative side waterproofing. There are specialized products for that.
What you need is something like this.
http://www.koester.eu/files/de_en/KOESTER-Systembrochure-Negative-Side-Waterproofing-Systems-for-Masonry-and-Concrete.PDF
Pagel Pakistan deals in Koester construction chemicals.
Welcome to Pagel Construction Chemicals - Pagel Pakistan