Section 216 is for non-residents with rental or timber royalty income.
Section 216 is for non-residents with ant of the following type of income:
Old age security (OAS) pension;
Canada Pension Plan or Quebec Pension Plan benefits;
superannuation or pension benefits;
registered retirement savings plan payments;
pooled registered pension plan payments;
registered retirement income fund payments;
death benefits;
employment insurance benefits;
retiring allowances;
registered supplementary unemployment benefit plan payments;
deferred profit-sharing plan payments;
amounts received from a retirement compensation arrangement or the purchase price of an interest in a retirement compensation arrangement;
prescribed benefits under a government assistance program;
Auto Pact benefits.
You can read more about Non-Resident Elective returns at the CRA website: https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/t4058/non-residents-income-tax-2016.html#P174_18675
If you are still unsure about you non-resident status, it would be best if you contacted the CRA directly. https://www.canada.ca/en/revenue-agency/corporate/contact-information/international-tax-non-resident...