I found these two-
But, I am not sure about reliability. Usually RBPs interact mRNAs with specific domains like RRMs, zinc-fingers etc. If I know which domain my protein has, I would data-mine literature to get probable RNA binding sequences. But if you have disordered regions in the protein or prion-like domains, it would be very hard to predict. You might look into these databases and tell us your opinion if it was useful or not! Also check the folding of the transcripts of this gene that you are testing using RegRNA http://regrna.mbc.nctu.edu.tw/html/prediction.html or mfold http://unafold.rna.albany.edu/?q=mfold. These tools are predictive, but hey if you're investigations turns out useful, you can use it to set an experiment to answer the protein-RNA interaction biologically.