Think about this : There is an space which has no air?

It is hard to understand what you are asking. I think you are asking, if there are two balls in a vacuum, one heavy and one light, which will hit the ground first when dropped. The answer is that both will hit at the same time. Provided there is no air resistance, any two objects dropped from the same height will hit the ground at the same time. This is because the acceleration due to gravity is (roughly) constant and does not depend upon the mass of the object.

I hope that this answers your question, but it is difficult to tell what you are asking.

Neither will arrive sooner. Weight is not a factor in the speed at which something falls. Gravity pulls all objects at 9.8 m/s^2 and since there is no air, air resistance does not exist.

Both objects will arrive at the same time.

Bad english, im assuming youre asking 'if two balls of different mass/shape/size are dropped in a vacuum, which will land first?'

the answer is: they will land at the same time! there is no air resistance in a vacuum, a lump of metal and a feather would fall at the same speed.

both will arrive at the same time. they both have free fall acceleration

Which one has more inertia?

I can't understand your poor english, please try asking again.