I have bought link from around 5 blogs that are highly related to niche. But later i found that those blogs are in supplemental results . If i am not wrong sites having duplicate content will go into supplemental results. Does backlinks from those pages count for pr. will those backlinks hurt my pr. Can i continue to have them or should i remove it? Please help me in this regard.
don't worry about who is linking TO your website, it cannot hurt your site's rankings. you only get a PR benefit if the page that your link is on has PR.
If I understood correctly, the page which has ZERO PR would not benefit to my website if I link to that page???
The blog pages could be in supplemental results maybe because the blogs are very new. Maybe you should wait for them to come out of the supplements and then get some PR benefit.
Think of it this way. It would be insane to hurt your rankings because of some link farm or whatever is linking to you. Why? Because you have no control over who is linking to you. If Google would ban someone for having "bad" links the it would be much easier to destroy your competition instead of making your site better then competition.
backlink is backlink . every link will help you (if they are not coming from a link farm). supplemental pages are the pages which are visited by googlebot with long period but they are being visited and link on those pages will be counted as backlinks