Yes, you can file previous years' returns. Use this link to choose which year you are filing for https://turbotax.intuit.ca/tax-software/prior-year-taxes.jsp
CRA asks that you should report the tuition fees on the year they were incurred even if you didn't have any income to report. The reason is that the laws about how to claim the credits, the type of credits you can apply for, the eligibility for transfers, the provincial credits, etc. changes every year.
I hope this was helpful
