Where does “სავალდებულო” come from?

სავალდებულო (Georgian) comes from Georgian სა- -ო, from Proto-Georgian-Zan *lʿa- -o.

Ancestry of “სავალდებულო”, step by step

Step	Language	Word	Meaning
1	Georgian	სა- -ო	—
2	Proto-Georgian-Zan	*lʿa- -o	—

სავალდებულო — Etymology, Origin & Word History | Etymology Explorer