What is the component in bluetooth module
In the picture, what is the component of above red box?
  


This looks like 2.402 GHz chip band pass filter like the one shown in the datasheet here.


  
    What is the component of below red box? Top of this component, It's written "DH=M6C". But I couldn't find any datasheets about "DH=M6C"
  


That may be 5 pin LDO for supplying the power to the module like this part.