Hi,

I have j-1 visa I am still in USA can I apply for canada work permit... its legal. or I have to complete my internship in the USA

Depends on your contract. If you are on J-1 that is subject to 2 yrs rule, you need to get a waiver first. If you're unable to obtain J-1 waiver, you are not eligible to either extend your stay in US or apply for new visa in Canada.

Yes I have 2 year rules apply on my j-1 visa... if sombody sponsor me from canada work permit than I can apply for this,and if I get marry with canadian girl.who have citizenship of canada..?