Declension table of ?kṛttavat

Masculine	Singular	Dual	Plural
Nominative	kṛttavān	kṛttavantau	kṛttavantaḥ
Vocative	kṛttavan	kṛttavantau	kṛttavantaḥ
Accusative	kṛttavantam	kṛttavantau	kṛttavataḥ
Instrumental	kṛttavatā	kṛttavadbhyām	kṛttavadbhiḥ
Dative	kṛttavate	kṛttavadbhyām	kṛttavadbhyaḥ
Ablative	kṛttavataḥ	kṛttavadbhyām	kṛttavadbhyaḥ
Genitive	kṛttavataḥ	kṛttavatoḥ	kṛttavatām
Locative	kṛttavati	kṛttavatoḥ	kṛttavatsu

Compound kṛttavat -

Adverb -kṛttavantam