In order to fit the R6 fairing to a Thundercat, you will need to:
* Modify the frame of the Thundercat to accommodate the R6 fairing. This may involve cutting and welding the frame.
* Fabricate new brackets to mount the R6 fairing to the Thundercat.
* Modify the bodywork of the Thundercat to fit the R6 fairing. This may involve cutting and shaping the bodywork.
* Paint the R6 fairing and bodywork to match the Thundercat.
It is important to note that these modifications are complex and time-consuming. It is not recommended that you attempt to perform these modifications unless you have experience with motorcycle fabrication and bodywork.