I have a site and the PR of home page is 1,can it fair if I do a link exchange with a PR 2 site but link page?
Do you mean for a 2 way link exchange? Your site and your prospective site? There is no problem with that as long that your prospective site is related with your site and if the webmaster of that prospective site agree with your offer.
Find some link extractor tool to check the OBL of the link page, if the number is smaller than your OBLx2 then its ok. Also check if the OBL links are relevant. Do not make link exchanges with non-relevant websites, for example casino link on health page.
Check PR of the specific pages where the actual links will be placed and not just the home page. If the others has high PR than yours then you can go with it. Relevancy is also an important factor to keep in mind while exchanging links.
In my opinion, PR does not matter anymore. RELEVANCE is what matters. Are you going to be doing a link exchange with a site relevant to your niche? If you are, that link counts for much more than a higher PR link that is completely irrelevant to your niche.
3 way exchange will be the best option for you. You can offer that site from any of your internal pages.