Declension table of ?tvacya

Neuter	Singular	Dual	Plural
Nominative	tvacyam	tvacye	tvacyāni
Vocative	tvacya	tvacye	tvacyāni
Accusative	tvacyam	tvacye	tvacyāni
Instrumental	tvacyena	tvacyābhyām	tvacyaiḥ
Dative	tvacyāya	tvacyābhyām	tvacyebhyaḥ
Ablative	tvacyāt	tvacyābhyām	tvacyebhyaḥ
Genitive	tvacyasya	tvacyayoḥ	tvacyānām
Locative	tvacye	tvacyayoḥ	tvacyeṣu

Compound tvacya -

Adverb -tvacyam -tvacyāt