Can I try applying once even if there is a risk of rejection for a Diploma/Postgraduate?

Yes, you can apply even if there's a risk of rejection.

Canadian postgraduate diploma programs often review applications holistically, not just on grades. Strengthen your application with a strong Statement of Purpose (SOP), relevant certifications, and strong letters of recommendation.

Including any work experience or additional skills can also help. Some institutions have more flexible admission policies and may consider applicants with lower GPAs.