sarjil,
mercury which is known as in jyotisham budhan,isprimary driver of buddhi or intellect.in any jyotisham chart rasi based on chandra laganam,then ascendant lagnam,and then surya lagnam,must be read in tottality to ascertain strength and weakness in a graham.amateurs like me,prolly read only the lagnam chart alone,to get a simple overview for the querant.the houses of budhan or lordship is,mithunam aka gemini and kanya aka virgo.usually budhan and suryan will be very close to each other.