Sun - Sun represents Personality, King, Government, Father, Authority, Career, Top Positions, Ego, Self Esteem, Health, Education etc.
Rahu - It represents Illusion, Foreign Lands, Foreign Things (foreign as in unknown things. So, for someone living in Punjab, culture and rituals of Kerala is also unknown and hence Foreign), Drugs, Medicines, any type of intoxication, Fame, Wealth, Success, Obsession, Past-life incomplete Desires, Movies, Television, Online World, Cheating, Imagined Fears, Unusual Things, Unique Things, Creativity, Rule breaker. Rahu also blows things out of proportions.
Sun-Rahu Conjunction - First thing which strikes in mind with this conjunction is that person is born near Solar Eclipse day of that year. Closer the degrees of Sun & Rahu, bigger the impact of eclipse on the person. 1st impact of this planetary position is that person's father may be absent from his life for any reason whatsoever. Sun is Father and as it is getting eclipsed, it shows that Father is getting eclipsed from person's life. It also means eclipse of Ego and Confidence related thing as generally these things get developed with presence and guidance of Father. Sun & Rahu are bitter enemies as per mythology and Rahu is the one who is grasping Sun. So, Rahu will anyhow impact Sun when they are in same house/sign. It may also create a situation where person may become proud for actually nothing which means false ego got blown-up by Rahu nature. As Sun is Career and Authority, it shows that during early life, these people will have no idea about their right Career. Even if they are in some Career and giving their best, authority will never come to them in early life. They may not get proper support from their authority figures, either at home or at work. As Rahu represents unique, foreign and unusual things, it shows that they will get success and authority by following some unique career or working with Foreign Companies etc. If Sun is in bad dignity, then it shows that person can be prepared to cheat others to gain in career and authority. But if Sun is in good dignity, then it shows that sooner or later Sun will be able to come out of eclipse and person will get authority and name in life through dignified ways.
The grasping impact of Rahu on Sun can be lesser if Sun is in good dignity like Sun exalted in Aries or Sun in own sign Leo. This is where Sun can have strength to deal with its enemy Rahu and come out as winner in this planetary war.
In other signs, Rahu will overpower Sun and remain a winner till its maturity age of 42 years. But as Buddha said, 3 things can’t be hidden for long; The Sun, The Moon and The Truth. So, Sun will come out of eclipse and shine bright after 42 years of age, no matter in which sign it is. We can also say that person will have a better idea about his path in life where he can gain in career, authority and confidence.
Hope this helps. Thanks,