Declension table of ?ṛṣīvat

Masculine	Singular	Dual	Plural
Nominative	ṛṣīvān	ṛṣīvantau	ṛṣīvantaḥ
Vocative	ṛṣīvan	ṛṣīvantau	ṛṣīvantaḥ
Accusative	ṛṣīvantam	ṛṣīvantau	ṛṣīvataḥ
Instrumental	ṛṣīvatā	ṛṣīvadbhyām	ṛṣīvadbhiḥ
Dative	ṛṣīvate	ṛṣīvadbhyām	ṛṣīvadbhyaḥ
Ablative	ṛṣīvataḥ	ṛṣīvadbhyām	ṛṣīvadbhyaḥ
Genitive	ṛṣīvataḥ	ṛṣīvatoḥ	ṛṣīvatām
Locative	ṛṣīvati	ṛṣīvatoḥ	ṛṣīvatsu

Compound ṛṣīvat -

Adverb -ṛṣīvantam