Yesterday morning I removed the charger plug from my phone and suddenly a message popped asking me to scan the SD card (I don't have any antivirus installed in the phone), I clicked Scan and when I checked my Photo gallery and music player , all my stuffs which I had on SD card were gone, My Sd card occupied space got reduced by 2 GB. Is there anyway to restore it ? I use Microsoft LUMIA 540..
You can use several programs like Recuva or Stellar Phoenix Data Recovery on your PC for recovering data. Connect your SD card as a removable disk to your PC and run a data recovery software. Scan the SD card (it'll take time, maybe 3 hours?). All the data still in the SD card and the deleted ones will appear on the screen. Restore it to your PC.
I'm sorry to say, but since it is about 6 months since you lost your data, there is a lower chance you can get it back. Anyway, try it. Note that you should use a full version of data recovery software to recover data back. With a trial version, you can only see the files.