The way the KeyMander is designed you can use the sample profile settings at any DPI between 2K and 10K and movement speed will be the same. However, having the mouse DPI set at 3500-5000 (with the KeyMander sensitivity set to match) will provide a smoother mouse feel. Once you have the mouse moving smoothly you can make small mouse sensitivity changes until you reach something that feels good to you. Keep in mind that R6S has a relatively low maximum turn speed compared to games like Call of Duty, so you can't just crank up the sensitivity blindly or you will reach a point where the mouse feels like it is laggy, indicating you have exceeded the game's max turn speed as explained here.

I use 10000 dpi is that fine?I

Yes, if your mouse runs at 10K, use that setting.

i have a hyperx pulsfire core dpi 800-6200 but when i set to 6200 i , feel very slow the sens in the game but if i set 800 i feel more faster, idk why this is happening

Did you change the DPI setting in the KeyMander software and remember to upload it to KeyMander? If not, you are at the default setting in the software (2000dpi) and 6200 on the mouse which is very likely causing you to hit the turn speed limit of the game as explained here.

Okay thanks, and what dpi you recommend me for rainbow six siege ?

Wdym with upload it to keymander

I recommend you set to 6200 for your mouse and set the KeyMander software to the same. Make sure you press the Upload button in the KeyMander software to Upload the profile to your KeyMander.

I dont know why but my sens is weird IT chaking IT not playable on R6