Declension table of ?nirmantra

Neuter	Singular	Dual	Plural
Nominative	nirmantram	nirmantre	nirmantrāṇi
Vocative	nirmantra	nirmantre	nirmantrāṇi
Accusative	nirmantram	nirmantre	nirmantrāṇi
Instrumental	nirmantreṇa	nirmantrābhyām	nirmantraiḥ
Dative	nirmantrāya	nirmantrābhyām	nirmantrebhyaḥ
Ablative	nirmantrāt	nirmantrābhyām	nirmantrebhyaḥ
Genitive	nirmantrasya	nirmantrayoḥ	nirmantrāṇām
Locative	nirmantre	nirmantrayoḥ	nirmantreṣu

Compound nirmantra -

Adverb -nirmantram -nirmantrāt