Declension table of mantratantra

Neuter	Singular	Dual	Plural
Nominative	mantratantram	mantratantre	mantratantrāṇi
Vocative	mantratantra	mantratantre	mantratantrāṇi
Accusative	mantratantram	mantratantre	mantratantrāṇi
Instrumental	mantratantreṇa	mantratantrābhyām	mantratantraiḥ
Dative	mantratantrāya	mantratantrābhyām	mantratantrebhyaḥ
Ablative	mantratantrāt	mantratantrābhyām	mantratantrebhyaḥ
Genitive	mantratantrasya	mantratantrayoḥ	mantratantrāṇām
Locative	mantratantre	mantratantrayoḥ	mantratantreṣu

Compound mantratantra -

Adverb -mantratantram -mantratantrāt