"Korkut chassis" is ACV-AD, ACV 30 by its previous name. It's a big vehicle, up to 30 tons.
Really doubt a steel hull ACV AD would weigh 20 tons with combat weight as claimed on their website.
To drive the point home, this is the best look we got on a Korkut Spaag ACV-AD(ACV-30) next to a regular ACV-15(in this case Aselsan's UGV tech demonstrator based on ACV-15T1). ACV-30 is huge compared to the 15.
photo credit
To clarify, as far as I'm aware, ACV-30 was based on the 18 ton ACV-19[Akıncı, originally ACV-S(tretched)]. ACV-19 is of course based on 14 ton ACV-15. Turkey is not a user of ACV-19 per my knowledge, but was exported to Jordan, Saudi Arabia and a mortar carrier version was made for Malaysia next to their ACV-300s, which is not related to ACV-30 but an ACV-15 with bigger 300hp engine. To sum up, ACV- 30 is an enlarged version of an enlarged version of ACV-15, which is the license production of an enlarged version of M113. M113 will live forever. So, ACV-30, which was made for army's air defence programs Korkut and Hisar-A, was never projected as an IFV or APC. To denote this, its name was changed to ACV-Air Defence instead.
Tried to find a weight figure for ACV-15T1, but it's also not announced in line with FNSS' new vehicles. They only give a general hp/ton figure now. But, this part from brochure is interesting: "Beyond today's combat requirements, the IFV-15T1 will continue to be the backbone of mechanized infantry until the first half of the 21st century." M113 is indeed eternal.