Declension table of tantra

Neuter	Singular	Dual	Plural
Nominative	tantram	tantre	tantrāṇi
Vocative	tantra	tantre	tantrāṇi
Accusative	tantram	tantre	tantrāṇi
Instrumental	tantreṇa	tantrābhyām	tantraiḥ
Dative	tantrāya	tantrābhyām	tantrebhyaḥ
Ablative	tantrāt	tantrābhyām	tantrebhyaḥ
Genitive	tantrasya	tantrayoḥ	tantrāṇām
Locative	tantre	tantrayoḥ	tantreṣu

Compound tantra -

Adverb -tantram -tantrāt