Unlike the other seven planets, Rahu & Ketu do not have their own zodiac signs. These are mathematical points/nodes intersecting the paths of the Sun and the Moon, causing eclipses on the Earth. Hence, these are treated as 'shadow' planets..
With respect to one's birth chart, one can perceive the favourable or unfavourable position of the Rahu, based on the following "symptoms":
Benefic Effects: Life longevity of grandparents' (maternal), gainful gambling, mobility, journey (including religious journeys), acts of valour & courage, sportive personality.
Malefic Effects: Weak health, undiscovered talents, no recognition for outstanding jobs, knee pain, remains motivation/inspiration for others, loss in property, jealous, unharmonial relation with parents, forgiving, obstacles at work.
It is difficult to judge or ascertain in which category a person exists. It is not usual that every benefic or malefic character would be affecting a person at the time. There can be mixed effects too. To reduce the malefic effects, the understated remedies can be considered suitable: