Declension table of ?upayantra

Neuter	Singular	Dual	Plural
Nominative	upayantram	upayantre	upayantrāṇi
Vocative	upayantra	upayantre	upayantrāṇi
Accusative	upayantram	upayantre	upayantrāṇi
Instrumental	upayantreṇa	upayantrābhyām	upayantraiḥ
Dative	upayantrāya	upayantrābhyām	upayantrebhyaḥ
Ablative	upayantrāt	upayantrābhyām	upayantrebhyaḥ
Genitive	upayantrasya	upayantrayoḥ	upayantrāṇām
Locative	upayantre	upayantrayoḥ	upayantreṣu

Compound upayantra -

Adverb -upayantram -upayantrāt