You can increase your website's PR by doing the following activities such as:
- Frequent updation of content in the website
- Keyword used for searching your website should be more valuable
- The content updated in your website should be related to the theme of your website.
- More Number of useful backlinks should be created for your website in the social websites which are all having the high PR.
By doing the above things regularly you can get your website high PR in a short priod of time.