Is lemlib supporting mixed drivetrain?

Since the 55w limit, our drive train will be made by 11w and 5.5w, so does lemlib or PROS support drivetrain with 11w and 5.5w in the same time?

Yes, LemLib supports mixed drivetrains (e.g., drivetrains with center traction wheels and omni wheels) through its configuration settings.

i mean 2 11w and 1 5.5w each side

LEMLIB is the best one

Yes, PROS treats 5.5w and 11w motors the same in terms of motor configuration, so lemlib should do the same

Just make sure that you have the correct cartridges selected in code. For the 5.5 watt motor this will be green, 18:1, 200 rpm, etc.