guys my friend and i have more than 250 websites. can using inter link exchange or content link, we can increase our PR? please suggest......
Getting backlinks from high PR sites (with few outbound links) which are thematic to your site's content/niche can increase your site's PR. So if your site matches the niche/content of your friend's and assuming your friend's site have high PR (PR4+) - your site can get the PR juice. Hope this answers your question.
c class is very important. if your websites are in same ip, links will not effect your PR. also, number of websites is not important. important detail is, value of the websites. if you have 1000 PR 0 backlinks, your website will be PR 1-2-3. but if you get a backlink from a PR 7 website, your website can be PR 4-5-6.
As long as all 250 websites are hosted on different IP (not on shared hosting or dedicated hosting with same IP) you will get benefit from it. Try not to excessively do the link exchanges as google can give some penalty for link exchanges. Also, if it is on the same IP, I would say it is a bad Idea and you might just reveal yourself with all 250 website to get penalty from google for interlinking your website.