Thanks for a details on your Birth chart, kindly note that the Gaja kesaro Yoga is not good, because Moon despite being exalted is most malefic planet or MMP in your horoscope as it is the 8th lord.
Second Yes Yellow Sapphire is strongly recommended, despite Jupiter being in the 12th house. Jupiter is the lagnesh and therefore its stone is strongly recommended. You should wear Yellow Sapphire on Your right hand Index finger on Thursday Morning for benefits.
Blessings,
Navneet Khanna
Astrologer