Return of Capital on a T3 does not need to be entered in your tax return. This amount is for information purposes only. Note that this amount will affect your ACB (Adjusted Cost Base) in the year you sell the mutual fund. Please refer to CRA publication RC4169 Tax Treatment of Mutual Funds for Individuals:
https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/rc4169.html