hi,
you must apply to belediye with your reasons to delay why you could not completed the project and request extra time to fix everything...they will reseach and give you more time...am sure with some extra cost, it depends on many points (your project type, land/house m2, how long it wd be complete etc.,)
I only suggest "do not be late" for like this formal application...
because some extra cost is always better than fine, good luck Blues
Neylan