That chassis looks to be one of those region-exclusive items.
https://mdcomputers.in/cooler-master-mid-tower-rc-250c-kkn3.html
CPU cooler height:
154mm / 6.0 inch (without side fan)
129mm / 5.1 inch (with side fan)
Deepcool Gammaxx has a version 1 and 2, and both are too tall for that chassis:
Version 1: 154.5mm
Version 2: 155mm