Declension table of upanayana

Neuter	Singular	Dual	Plural
Nominative	upanayanam	upanayane	upanayanāni
Vocative	upanayana	upanayane	upanayanāni
Accusative	upanayanam	upanayane	upanayanāni
Instrumental	upanayanena	upanayanābhyām	upanayanaiḥ
Dative	upanayanāya	upanayanābhyām	upanayanebhyaḥ
Ablative	upanayanāt	upanayanābhyām	upanayanebhyaḥ
Genitive	upanayanasya	upanayanayoḥ	upanayanānām
Locative	upanayane	upanayanayoḥ	upanayaneṣu

Compound upanayana -

Adverb -upanayanam -upanayanāt