I finally got the solution.
I downloaded both Visual Studio 2013, and update 2 RC using the /layout switch at command prompt. From MSDN:
After you download the update executable from the MSDN website to a location on your file system, run the following command at a command prompt: /layout.
This command downloads all the packages for the installation. By using the /layout switch, you can download all the installation packages, not just the ones that apply to the download machine. This approach gives you all the files that you need to run this update anywhere and may be useful if you want to install components that weren't installed originally.
To do this, download the Visual Studio 2013, and Visual Studio 2013 Update 2 RC files (about 2-3 MBs each). Then, create a shortcut of these files on desktop, and then open properties of shortcut. In target field after ", add a space followed with /layout as shown below:
This will download all installation files to your disk and when you install the VS (the exe at specified download folder), it won't ask it to fetch from internet, rather will do it from offline files and phone SDK 8.1 will be installed too.
Please be warned that, this will take a lot of time. To save time, I suggest following what is in Update section.
Update
While searching on internet, I found these two links on Microsoft website:
Microsoft Visual Studio Express 2013 for Windows Desktop
Microsoft Visual Studio Express 2013 for Windows with Update 2
In download section, these two sites show that, the offline download option is now available (as evident from the ISOs shown). Though, I don't know if that would help as I haven't tested this option. Just that this option will be much more quicker than using /layout switch.