The only way to recognise your MBBS credential in Canada is to get it evaluated by any agency, e.g. WES.
Now, WES will count your internship as a part of MBBS, the total duration of which is 5.5 years. It would say in your ECA report, 'Professional degree needed to practise in a licensed profession'.
Um... this is not correct. To have a medical degree assessed, it can ONLY be assessed by the Medical Council of Canada (a WES evaluation would not be accepted.)
See the section "Designated Organizations for ECAs" -
http://www.cic.gc.ca/english/immigrate/skilled/assessment.asp
And, also MBBS degree can't be earned without internship. So, it can't be calculated as work experience.
I disagree with this. If the experience is outside of Canada, then student work can be accepted. For example, if someone works as a Teaching or Research Assistant as part of their studies, this experience is accepted.
So, yes, the internship is accepted as skilled work experience.
http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=855&top=29
Also you will note that intern and resident are included in the NOC.