The majority of people will not receive an RC62 for the 2017 tax year. 

The slip will still be issued to anyone who received "back pay" for UCCB benefits prior to July 2016, or if you had to make a repayment. If you did make a repayment, you should receive an RC62 (CRA will have this information available for you) and only then should you include that payment on your tax return. 

https://www.canada.ca/en/revenue-agency/services/child-family-benefits/canada-child-benefit-overview...