The Rudraksha for Cancer is 2 Mukhi Rudraksha and the ruling planet is Moon.

The people of sun sign Cancer are understanding, generous, deepest emotional, authentic, happiest introvert, always loves to see everyone happy around them. The world of fantasy leads their life rather than the positive world in most situations. 

The 2 Mukhi Rudraksha improves the social bonds, helps in integration. Creates a practical world reality check and makes them fit for the fight of life. It helps in rehabilitating emotional instability, liberates from fear and insecurities.