Red Dead Redemption 2 Real Life Lighting ULTRA Graphics Mod RTGI and Non RTGI Download Page

Reshade -
Preset -
RTGI 0.20 By Pascal Glicher -

Open reshade setup, select RDR2.exe select all effects and install as Vulkan
Install RTGI Shaders
Put preset RDR2_KTMX.ini and RDR2 NON RTGI.ini in \Red Dead Redemption 2 folder
Open game, press 'home" and select preset.
RDR2 NON RTGI.ini is for without RTGI.
If RTGI is not working, go to Vulkan tab from reshade menu and select this option