Declension table of ?karmaṇya

Neuter	Singular	Dual	Plural
Nominative	karmaṇyam	karmaṇye	karmaṇyāni
Vocative	karmaṇya	karmaṇye	karmaṇyāni
Accusative	karmaṇyam	karmaṇye	karmaṇyāni
Instrumental	karmaṇyena	karmaṇyābhyām	karmaṇyaiḥ
Dative	karmaṇyāya	karmaṇyābhyām	karmaṇyebhyaḥ
Ablative	karmaṇyāt	karmaṇyābhyām	karmaṇyebhyaḥ
Genitive	karmaṇyasya	karmaṇyayoḥ	karmaṇyānām
Locative	karmaṇye	karmaṇyayoḥ	karmaṇyeṣu

Compound karmaṇya -

Adverb -karmaṇyam -karmaṇyāt