Declension table of ?vastutantra

Masculine	Singular	Dual	Plural
Nominative	vastutantraḥ	vastutantrau	vastutantrāḥ
Vocative	vastutantra	vastutantrau	vastutantrāḥ
Accusative	vastutantram	vastutantrau	vastutantrān
Instrumental	vastutantreṇa	vastutantrābhyām	vastutantraiḥ vastutantrebhiḥ
Dative	vastutantrāya	vastutantrābhyām	vastutantrebhyaḥ
Ablative	vastutantrāt	vastutantrābhyām	vastutantrebhyaḥ
Genitive	vastutantrasya	vastutantrayoḥ	vastutantrāṇām
Locative	vastutantre	vastutantrayoḥ	vastutantreṣu

Compound vastutantra -

Adverb -vastutantram -vastutantrāt