Declension table of ?ṛtva

Neuter	Singular	Dual	Plural
Nominative	ṛtvam	ṛtve	ṛtvāni
Vocative	ṛtva	ṛtve	ṛtvāni
Accusative	ṛtvam	ṛtve	ṛtvāni
Instrumental	ṛtvena	ṛtvābhyām	ṛtvaiḥ
Dative	ṛtvāya	ṛtvābhyām	ṛtvebhyaḥ
Ablative	ṛtvāt	ṛtvābhyām	ṛtvebhyaḥ
Genitive	ṛtvasya	ṛtvayoḥ	ṛtvānām
Locative	ṛtve	ṛtvayoḥ	ṛtveṣu

Compound ṛtva -

Adverb -ṛtvam -ṛtvāt