Declension table of brahmaputra

Masculine	Singular	Dual	Plural
Nominative	brahmaputraḥ	brahmaputrau	brahmaputrāḥ
Vocative	brahmaputra	brahmaputrau	brahmaputrāḥ
Accusative	brahmaputram	brahmaputrau	brahmaputrān
Instrumental	brahmaputreṇa	brahmaputrābhyām	brahmaputraiḥ brahmaputrebhiḥ
Dative	brahmaputrāya	brahmaputrābhyām	brahmaputrebhyaḥ
Ablative	brahmaputrāt	brahmaputrābhyām	brahmaputrebhyaḥ
Genitive	brahmaputrasya	brahmaputrayoḥ	brahmaputrāṇām
Locative	brahmaputre	brahmaputrayoḥ	brahmaputreṣu

Compound brahmaputra -

Adverb -brahmaputram -brahmaputrāt