I paid my sons college tuition but I did not claim him as a dependent. Can i claim his tuition expense? Thank You

If you do not claim your son as a dependent, you cannot claim his tuition, even if you paid the tuition.

If he is filing independent, he can claim the tuition money you paid,  in claiming a credit or deduction on his return.

If the other parent is claiming him as a dependent, he/she can claim what you paid   in claiming a credit or deduction.