Garudapurana 3.28.42

3.28.42

atiprakāśayuktatvāttasmādrugmavatī smṛtā /
duryodhanasya yā putrī lakṣaṇā sā ratiḥ smṛtā //

because she was endowed with extraordinary brilliance, she is remembered as Rukmavatī.
Duryodhana's daughter Lakṣaṇā is remembered as Rati;