Rahu and Ketu are shadows but not general planets like other seven. But Rahu and Ketu in modern days have most influence on a person’s horoscope. Out of many combinations of rahu – ketu placements in a horoscope, all planets being within rahu – ketu and rest 7 houses being empty is said to cause Kalasarpa yoga or dosha. It can be a yoga or dosha based on other planets conjunct with rahu or ketu, owners of houses occupied by rahu - ketu, planets affecting it and also position of them with respect to lagna. Individuals  who have naga dosha should also  perform the puja

Who should do this Puja: Individuals who are affected by delay in marriage, delay in child birth , issues relating to family dispute like divorce ,separation,  , loss of job , loss in business, issues that are negative in nature

When you should do this Puja: Whenever identified in horoscope

Benefits of this Puja : Performing the puja  leads to happiness, prosperity and good health.  removes obstacles or hurdles at work, in business and personal  life.