Jaiveerdeep, the saved pages can be opened in the offline mode as its database is saved in your phone and the next time when you open it you won't need any internet connection. This is because your browser just finds that file saved in your computer and opens it quickly without the need of any internet connection. But when you save a bookmark of any page, the phone just saves that link in the browser and hence no file is saved. So the next time when you open that page or link, an internet connection is required to open that link because there is no database saved in the phone. So for saving the page in your phone, you should use the steps given below:
1. Download Opera mini browser in your phone as it uses very less data and saves pages quickly without the need of any extension.
2. Open Opera mini after the installation is complete. And open any of the site which you want to save.
3. If you are using an Android phone then click on the top left corner and click on save page and click on the fist text which will be with a plus sign. If you are using a Symbian phone than just click the options button and directly select save page button.
Hope this would help you solve your problem.