I present below the holy Sudarshana Mantra..It is dedicated to the mighty holy discus of Lord Mahavishnu, to whom the devotee asks for protection. The amntra is as follows :-

OM KLEEM KRISHNAYA HREEM
GOVINDAYA SHREEM GOPI JANA
VALLABHAYA OM PARAYA PARAMA
PURUSHAYA PARAMATHMANE MAMMA PARA
KARMA MANTRA YANTRA TANTRA
AOWSHADA ASHTRA SASHTHRA SAMHARA
MRYTHOR MOCHAYA MOCHAYA
OM MAHA SUDARSHANAYA DHEEPTHRE
JWALAAH PAREEVRUTHAYA SARVATHIK
SHOBANA KARAYAH HUMPHAT PARABRAHMANE SWAHA
OM MAHA SUDHARSHANADHARAYA NAMA ITHAM

Prostrate to Lord Mahavishnu and the mighty Sudarshana Chakra to remove all evil entities and miseries from your life. A daily recital of 54 times is recommended for fast relief.

Hari Om...thanx a lot...i had been looking for this mantra for quite sometime..I'v heard it being used in Sudarshana Homas in temples