Declension table of ?ṣaṣṭivrata

Masculine	Singular	Dual	Plural
Nominative	ṣaṣṭivrataḥ	ṣaṣṭivratau	ṣaṣṭivratāḥ
Vocative	ṣaṣṭivrata	ṣaṣṭivratau	ṣaṣṭivratāḥ
Accusative	ṣaṣṭivratam	ṣaṣṭivratau	ṣaṣṭivratān
Instrumental	ṣaṣṭivratena	ṣaṣṭivratābhyām	ṣaṣṭivrataiḥ ṣaṣṭivratebhiḥ
Dative	ṣaṣṭivratāya	ṣaṣṭivratābhyām	ṣaṣṭivratebhyaḥ
Ablative	ṣaṣṭivratāt	ṣaṣṭivratābhyām	ṣaṣṭivratebhyaḥ
Genitive	ṣaṣṭivratasya	ṣaṣṭivratayoḥ	ṣaṣṭivratānām
Locative	ṣaṣṭivrate	ṣaṣṭivratayoḥ	ṣaṣṭivrateṣu

Compound ṣaṣṭivrata -

Adverb -ṣaṣṭivratam -ṣaṣṭivratāt