My parents claimed me on their return last yr & I didn't get stim money. If I claim myself on 2020 taxes can I get the money through the recovery rebate credit?

It depends.  If you file as individual and your income falls under the income requirement threshold, then you may claim the sitmulus as recovery rebate credit on your 2020 tax return.  Most taxpayers who are eligible for the Recovery Rebate Credit already received the first and second stimulus payments.  You  need to fill up the Recovery Credit form on the return and enter zero on both 1st and second stimulus payments line to claim the credit.

See, pub 5848, recovery rebate credit, link