Declension table of yantra

Neuter	Singular	Dual	Plural
Nominative	yantram	yantre	yantrāṇi
Vocative	yantra	yantre	yantrāṇi
Accusative	yantram	yantre	yantrāṇi
Instrumental	yantreṇa	yantrābhyām	yantraiḥ
Dative	yantrāya	yantrābhyām	yantrebhyaḥ
Ablative	yantrāt	yantrābhyām	yantrebhyaḥ
Genitive	yantrasya	yantrayoḥ	yantrāṇām
Locative	yantre	yantrayoḥ	yantreṣu

Compound yantra -

Adverb -yantram -yantrāt