The other sites I checked all show the 60 and 62 size codes identical to the information I provided in my first response.
The information provided for the Gorka suit on the Rus-Mil site shows consistently larger sizes than indicated on other sites. The Rus-Mil site also changes the chest and waist dimensions for each size code depending on what product you are looking at. Because the Gorka suit is meant as an outer layer, I think they are using the standard size codes, but showing the larger dimensions so you can decide if it will fit over your regular clothes.
From the Rus-Mil Gorka suit page: 60-62/182-188 = 47" to 50" waist and 52" to 55" chest for someone 5' 11" to 6' 2" tall.
The next size down on the same chart is: 56-58/182-188 = 44" to 47" waist and 49" to 52" for someone 5' 11" to 6' 2" tall.
There is a "What are you wearing under there?" joke just waiting for someone to let their guard down.