if the motifs are binding sites for RNA binding proteins i would suggest ATtRACT because is more updated, it contains more motifs, and all of them experimentally validated
http://attract.cnic.es/
if you are interested:
paper
If they're RNA motifs try the motif scan in CIS-BP-RNA to find related motifs from RNA-binding proteins using Tomtom. If they're DNA try the motif scan in CIS-BP to find related motifs from TFs using Tomtom.
Thanks a lot for your information