If the student loan is in your parents' names (PLUS), then they will have to claim any student loan interest deductions.
Student loan interest reported on the Form 1098-E can only be claimed by the person (or persons) who are legally responsible for the loan. Unless you were a co-signer on the loan, you can't claim a deduction for any interest paid.
For additional information, see "Can I claim my student loan?"
https://ttlc.intuit.com/replies/3302319