As per your details native born in Gemini ascendant , Rahu Sun Venus are in 8 th place. Sun is for 3 rd house, Venus is the lord of 5 & 12 th places.
Basically Rahu Sun combination is not good. Sun will be weak with Rahu so Sun related things will be affected. For example Sun in for Father , administration, fame , dignity, ruling abilities & political influence. So native will losses these things when Sun is with Rahu.
Then 8 th place is not good place for Sun & Venus. So native will not gets the support of his father. After his birth his father has faced lot of problems in his career. Sometimes he has faced life threats.
Native will faces legal issues with government side. If native is a business person sure he will be faced issues with income tax department. Money will be lost coz of tax .
Native love life will be ended with separation. Native has faced hurdles in getting of kids.
If native is male he will faces issues with his wife. Her health may be affected. Relationship with her will not be compatible.
If native is female sure she will be annoyed by negative thoughts. She will be tortured herself. Sometimes she will try to committe suicide coz of negative thoughts & mental depression.