When the Planets Rahu and Ketu surround all other planets and rest 7 houses being empty is said Kala Sarpa Dosha or yoga. Unusual and unexpected incidents happen in a person's life like child problems, loss in business, family problems etc.
This Pariharam is performed by invoking Rahu and Ketu and chanting mantras to please the Graha and the homam is performed as per the shastras to get rid of all the problem occurring due to this dosha.

Nag Pratishta Puja is one of the important Kaal Sarpa Dosha pujas performed at Rameshwaram. This will help ward off any Sarpa Dosha and give prosperity to one and all. This is the one of the most important remedies for those people who are suffering from Kaal Sarpa Dosha. According to ancient holy texts, any person having the Kaal Sarpa Yoga in their Kundali or horoscope suffers from the malefic effects of the Kaal Sarpa Dosha. This is especially bad when the person has Rahu Dosh in his horoscope as well. The person faces a lot of difficulty in life and has a lot of problems too.