Question

which is the biggest solar system

Answer 1

The biggest solar system has not been given a name so far. However, it has been found that this solar system has only one planet. This planet revolves around its distant sun like star called Kepler-90. The planet has been named Kepler-90i after its star and is very hot and rocky. Interestingly, the planet is about 12 to 15 times heavier than Jupiter, the largest planet of our solar system. It takes a million years to complete a single revolution around its sun.

Answer 2

The biggest known solar system consists of a large planet that takes nearly a million years to orbit its star. This planet is known as "2MASS J2126-8140" and is 12 to 15 times the mass of Jupiter and located about 100 light years away from Earth. 
2MASS J2126-8140's distance from its star is 7000 times the distance between Earth and sun making it's orbit 140 times wider than Pluto's path around our sun. This makes it the widest orbit of any planet around a star by a significant margin. 
By estimating the star's age, researchers say that the planet is somewhere between 10 to 45 million years old. This means that it has completed less then 50 orbits around it's star in total.