It is not clear whether Jura's rearrangement is correct. Is the whole thing about the "amis tribe"? if "in the Amis tribe" applies to all then as Jura says, maybe better at the beginning. Either way a small point is that the organisation is singular & should coolocate with to carry out or carries out. So There are two most impressive characteristics: one is that the matriarchal society and the other is their social organization through male work ranks to carry out community chores more effectively and quickly in the Amis tribe. <remove "that"> or There are two most impressive characteristics: one is that the matrilineal society and the other is that their social organization through male work ranks carries out community chores more effectively and quickly in the Amis tribe. is the organisation to carry out is that the organisation carries out

There are two most impressive characteristics in the Amis tribe: one is their matriarchal society and the other is that their social organization through their male ranks, carry out community chores effectively and quickly .