If he was 24 on dec 31 you can not claim him if he made more than 4,300. Has to be under 24 and a full time student. If he turned 24 during 2020 he is too old to claim full time student.
Who can I claim as a dependent?
https://ttlc.intuit.com/community/credits-and-deductions/help/who-can-i-claim-as-my-dependent/00/267...
Who you can claim article
https://turbotax.intuit.com/tax-tips/family/rules-for-claiming-a-dependent-on-your-tax-return/L8LODb...
