Can I do a PG Diploma in Canada after 3-year under graduate degree?

You can definitely go for PG Diploma/Graduate certificate programs in Canada. Programme can be of 1 or 2 years. Ontario and British Columbia provinces have very good colleges. Make sure you clear IELTS exam with 6.5 bands. You can check this website for programme details: ontariocolleges.ca

1. Computer Networking and Technical Support 2. Computer Programmer 3. Computer Programming and Analysis - (Optional Co-op) 4. Computer Systems Technology - (Optional Co-op) These are list of good courses you can opt for. They all are available in Seneca College (Toronto) You can check their website