Athletes who don’t make the weight +2kg will have the option of wrestling in the weight class that their weight puts them in. 

For example,

Weight class: 55 kg

+2 kg allowance = 57 kg

At last call the wrestler weighs in at 57.1 kg

OPTION 1:Then they have the option of wrestling in the 60 kg +2 kg weight class. With the 2 kg allowance, that weight class would have athletes weighing in as heavy as 62 kg.

OPTION 2: Their other option would be to not compete.