Declension table of ?upasthaka

Neuter	Singular	Dual	Plural
Nominative	upasthakam	upasthake	upasthakāni
Vocative	upasthaka	upasthake	upasthakāni
Accusative	upasthakam	upasthake	upasthakāni
Instrumental	upasthakena	upasthakābhyām	upasthakaiḥ
Dative	upasthakāya	upasthakābhyām	upasthakebhyaḥ
Ablative	upasthakāt	upasthakābhyām	upasthakebhyaḥ
Genitive	upasthakasya	upasthakayoḥ	upasthakānām
Locative	upasthake	upasthakayoḥ	upasthakeṣu

Compound upasthaka -

Adverb -upasthakam -upasthakāt