Declension table of ?manasin

Neuter	Singular	Dual	Plural
Nominative	manasi	manasinī	manasīni
Vocative	manasin manasi	manasinī	manasīni
Accusative	manasi	manasinī	manasīni
Instrumental	manasinā	manasibhyām	manasibhiḥ
Dative	manasine	manasibhyām	manasibhyaḥ
Ablative	manasinaḥ	manasibhyām	manasibhyaḥ
Genitive	manasinaḥ	manasinoḥ	manasinām
Locative	manasini	manasinoḥ	manasiṣu

Compound manasi -

Adverb -manasi