The tower of my house is in German stone... Not very aesthetic, some cracks and joints dug... A simple patching fibers or resin, not covered to leave a raw appearance, would it likely to adhere to this support?
I imagine this "tower" is a terrace? If you want to keep this apparent coating, you can clean it, fill in the cracks and repair the joints. You can then protect it with a water-repellent product that prevents the penetration of water and grease into the materials, while allowing them to "breathe".
A patch will cover all the coating, but it can not constitute an apparent surface. It only serves to regulate the surface and make it flat and smooth. You will then have to install a new one on top: tiling, floor or grating according to your taste. OMNICHAPE FIBER from PAREWLANKO is perfect for this job.
This may interest you