When 2 or more planets are in Uchh Rashi or in Kendra, the Karaka Yoga in astrology is said to be formed. In Vedic Astrology, Jupiter is the Karak for marriage, happiness and children. Sun is also considered the Karak planet which is capable to bring name and fame for the native. It also assists to get a government job.
Mars is the Karak planet which is said to bring courage, hope and many good things. These are natural significations when planets are Karak. In case, Jupiter is situated in the 4th house in cancer, the Karaka Yoga effects are positive in many ways. The native lives a happy life. He will be a lucky guy. His professional life will be quite good. His relation with mother is good. He may be able to get immovable assets. Make sure the effects of planets are not malefic. If they are, the Karak Yoga will be ineffective.