Declension table of ?parvatya

Neuter	Singular	Dual	Plural
Nominative	parvatyam	parvatye	parvatyāni
Vocative	parvatya	parvatye	parvatyāni
Accusative	parvatyam	parvatye	parvatyāni
Instrumental	parvatyena	parvatyābhyām	parvatyaiḥ
Dative	parvatyāya	parvatyābhyām	parvatyebhyaḥ
Ablative	parvatyāt	parvatyābhyām	parvatyebhyaḥ
Genitive	parvatyasya	parvatyayoḥ	parvatyānām
Locative	parvatye	parvatyayoḥ	parvatyeṣu

Compound parvatya -

Adverb -parvatyam -parvatyāt