As iam going to join for one year post garduate diploma in construcion management, after that when i can apply for PR, tell me the procedure how and when i can apply
It's not possible to say if or when you will qualify for PR based on the information you have provided.
Once you finish your studies, you will either need to secure a full time job and/or get experience working in Canada before you will qualify to apply for PR.
Finishing a PGD in Canada isn't enough to apply for PR.