I lived in student residence in Ont. for 4 mos and paid rent in a shared house for 8 mos. My parents are in Toronto, I return for summer. Can I claim rent? if so Where?

You can claim the rent you paid for 8 months. There is also a very small credit for living in a student residence which you can claim on a later page.

Where do I claim it?

You would claim your rent in the Provincial section as part of the Trillium credit.