Someone messed up. At a ba re minumium there should have been Tap Con screws use inside the tracks screwed to the concrete to keep the window from moving.
On the outside most often you'll see vinyl brick moulding used to trim out the window then low expanding foam is used to fill any gaps, not silicone.
If the plan is to finish out the basement There should be jamb extentions made that will hid the gaps on the outside edges.
On the outside most often you'll see vinyl brick moulding used to trim out the window then low expanding foam is used to fill any gaps, not silicone.
If the plan is to finish out the basement There should be jamb extentions made that will hid the gaps on the outside edges.