Declension table of ?tatvacāna

Masculine	Singular	Dual	Plural
Nominative	tatvacānaḥ	tatvacānau	tatvacānāḥ
Vocative	tatvacāna	tatvacānau	tatvacānāḥ
Accusative	tatvacānam	tatvacānau	tatvacānān
Instrumental	tatvacānena	tatvacānābhyām	tatvacānaiḥ tatvacānebhiḥ
Dative	tatvacānāya	tatvacānābhyām	tatvacānebhyaḥ
Ablative	tatvacānāt	tatvacānābhyām	tatvacānebhyaḥ
Genitive	tatvacānasya	tatvacānayoḥ	tatvacānānām
Locative	tatvacāne	tatvacānayoḥ	tatvacāneṣu

Compound tatvacāna -

Adverb -tatvacānam -tatvacānāt