Declension table of ?yantavya

Neuter	Singular	Dual	Plural
Nominative	yantavyam	yantavye	yantavyāni
Vocative	yantavya	yantavye	yantavyāni
Accusative	yantavyam	yantavye	yantavyāni
Instrumental	yantavyena	yantavyābhyām	yantavyaiḥ
Dative	yantavyāya	yantavyābhyām	yantavyebhyaḥ
Ablative	yantavyāt	yantavyābhyām	yantavyebhyaḥ
Genitive	yantavyasya	yantavyayoḥ	yantavyānām
Locative	yantavye	yantavyayoḥ	yantavyeṣu

Compound yantavya -

Adverb -yantavyam -yantavyāt