Declension table of ?ṛkvan

Neuter	Singular	Dual	Plural
Nominative	ṛkva	ṛkvṇī ṛkvaṇī	ṛkvāṇi
Vocative	ṛkvan ṛkva	ṛkvṇī ṛkvaṇī	ṛkvāṇi
Accusative	ṛkva	ṛkvṇī ṛkvaṇī	ṛkvāṇi
Instrumental	ṛkvaṇā	ṛkvabhyām	ṛkvabhiḥ
Dative	ṛkvaṇe	ṛkvabhyām	ṛkvabhyaḥ
Ablative	ṛkvaṇaḥ	ṛkvabhyām	ṛkvabhyaḥ
Genitive	ṛkvaṇaḥ	ṛkvaṇoḥ	ṛkvaṇām
Locative	ṛkvaṇi	ṛkvaṇoḥ	ṛkvasu

Compound ṛkva -

Adverb -ṛkva -ṛkvam