Declension table of mantṛ

Masculine	Singular	Dual	Plural
Nominative	mantā	mantārau	mantāraḥ
Vocative	mantaḥ	mantārau	mantāraḥ
Accusative	mantāram	mantārau	mantṝn
Instrumental	mantrā	mantṛbhyām	mantṛbhiḥ
Dative	mantre	mantṛbhyām	mantṛbhyaḥ
Ablative	mantuḥ	mantṛbhyām	mantṛbhyaḥ
Genitive	mantuḥ	mantroḥ	mantṝṇām
Locative	mantari	mantroḥ	mantṛṣu

Compound mantṛ -

Adverb -mantṛ