Since we do not provide that cable, I would recommend checking sites like:
However since you are located in India, you migth want to check with any local computer store to see if they have that cable.
Or you can also check with any Authorized Intel(R) Distributor, please access the following link and select a location, to find the closest authorized distributor:
YasithM, I would need to inform you that this motherboard is no longer under support since June 2012. http://www.intel.com/support/motherboards/desktop/sb/CS-033578.htm
For any audio problems, the following link will provide you the recommended troubleshooting. Also, check if the board needs a BIOS update.