Hello ajaysonu,
And welcome to Apple Discussions!
Is restoring & formatting same thing??? How do i Format it??
No, they are not. Restoring the iPod will only delete all the content from the iPod and set it back to its original default settings. Formatting the iPod will wipe everything and rebuild the drive's file system. So, formatting goes just one step further really.
However, if your iPod's sound isn't working, formatting it will have no effect because the problem probably lies with the hardware of the iPod itself, usually the headphone jack or the motherboard. You might want to consider getting your iPod serviced. As to where, that is up to you. There are a plethora of third party repair companies out there who will only charge a small fee to diagnose the problem as well as charge you a bit more to repair it as well.
B-rock
