A couple with a dependent n would like to file his own return. How do I includ his return coupled with his parents or do i need to create one completely indep from them

You don't need to do a return for the dependant that wants to do his own return. Instead, you'll simply ask the dependant to give you the amounts you need to couple his parents return. You'll need his income from line 236 of his return and the amount of tuition he indicated he'd be transferring to his parents.

This FAQ describes where to enter his tuition transfer amounts into the parent's return: https://turbotax.community.intuit.ca/replies/2647703