It always depends on the game, Even a 3090ti can have trouble on some games at 1080p and not able to obtain 120fps, its just how optimized said game is and sites that say that you can get this or that performance isn't always accurate, actually its rare that they are accurate.
But at 1080p 120hz is pretty decent match for the 3060 mobile, there will be plenty of games where it will get 120 fps or more, but some that it wont, but thats any graphics card out there.