Declension table of vastavya

Masculine	Singular	Dual	Plural
Nominative	vastavyaḥ	vastavyau	vastavyāḥ
Vocative	vastavya	vastavyau	vastavyāḥ
Accusative	vastavyam	vastavyau	vastavyān
Instrumental	vastavyena	vastavyābhyām	vastavyaiḥ vastavyebhiḥ
Dative	vastavyāya	vastavyābhyām	vastavyebhyaḥ
Ablative	vastavyāt	vastavyābhyām	vastavyebhyaḥ
Genitive	vastavyasya	vastavyayoḥ	vastavyānām
Locative	vastavye	vastavyayoḥ	vastavyeṣu

Compound vastavya -

Adverb -vastavyam -vastavyāt