Natal Pluto is the sign where your Pluto was placed during birth time, and from there other houses are calculated clock-wise.
If you were born with Pluto in Scorpio, then your natal house is Scorpio (Vrischika Rasi) and during transit, SUN forming conjunction (in Scorpio), sextile (aspect of 60° which are Virgo and Capricorn in this case), square (aspect of 90° which are Aquarius and Leo here), trine (aspect of 120° which are Cancer and Pisces here), opposition (aspect of 180° which is Taurus here) are discussed in this article.
Conjunction is transiting through same sign as in birth chart, sextile is transiting 3rd or 11th house, trine is transiting 5th or 9th house, opposition is transiting 7th house from natal sign.
Transit Sun conjunct Natal Pluto: Self assertion and changes characterize this transit. The individual tries to eliminate useless outworn ideas, may involve himself in new sexual experiences due to strong sexual stimulus. Radical changes is the key note of this transit. So the native is related to the advanced scientific and technological activities. In the charts of dominating nature where the Sun or Pluto is afflicted the native tries to dictate or coerce others, for his self assertive tendencies during this transit.
Transit Sun Sextile Natal Pluto: Endurance, resourcefulness and enhanced will power characterize this transit. The period to set right the confused and disordered situations. The native takes interest in group activities, metaphysical studies and in science and technology. The native may enjoy sexual pleasures with someone in the group where he is engaged as there is attraction for such an act if the horoscope promises.
Transit Sun Square Natal Pluto: The native is compelled to revolt against the prevalent system, incurs the wrath of superiors and is called upon to explain his working and actions. There is aggressiveness and jealousy in sexual relationships and the native is harsh towards his romantic partners. Psychic dangers are present if the native involves himself in occult or practice of black magic. There is danger to the native from hidden or behind the scene activities.
Transit Sun Trine Natal Pluto: Self expression, strong will power, self control, leadership characterize this transit. The native executes his plans forcefully and changes and reforms will be easily made. An excellent period for research and scientific investigation. One native is initiated into new romantic relationship, the other may go towards spiritual practices due to his own chart.
Transit Sun opposite Natal Pluto: Dominance, resentment and friction characterize this transit. There are conflicts over power and setting the things right. Sexual conflicts arise in marital and romantic relationships as the native is too much demanding. A little analytical approach is needed to gain from dynamic and forceful people.