In the horoscope the sign is on the cusp of each house. Aplanet alwasys occupies the sign and it's strength is determined according as it occupies it's own sign, exalted sign or debilitated sign. So the occupant is stronger than the owner of the sign.
Similarly, the Sign is the 1/12 th part of the Zodiac, while the Constellation or Star is the 1/27 th part of the Zodiac. So the Constellation or Star is stronger than the Sign.
Hence in the Nakshatr system which is the real Vedic system a planet gives the results indicated by it's star lord and it is called the significator of the houses signified by it's star lord in the strict sense of the term.
The order of preference regarding the significators of each house is generally determined as under :-
(a) A planet in the star of the occupant is stronger than occupant.
(b) If there be no planet in the occupant's star consider the occupant.
(c) If the house is vacant, consider the planet in the star of the owner of that house.
(d) If the house be vacant and if there be no planet in the star of the owner of that house, consider
the owner of that house.
(e) A planet in conjunction or association with, or aspected by the strong significator gives the results
of the house or houses denoted by that significator.
(f) A planet in the star of the planet aspecting the house e.g. supose Saturn in 5th house and it
aspects the 7th, 11th and 2nd house. So the planet in the star of saturn will give the results of the
2nd , 7th , and 11th house.