Hi Rakesh,
I'm not sure what your query is or what help it is you seek. If, it is the fact that you have 6GB RAM in your machine & yet, it is seeing 3.25 as useable... this is right & normal. It simply means you have a 32-bit machine & or OS. x86 stops @ 3.25, no matter how much RAM is actually in the machine. x64 will see & use more.
Cheers,
Drew