In the domestic fan i.e the induction motor can replace with BLDC motor give your suggestion on this issue

Ya it can be replaced and it will be more efficient and will consume les wattage.
Also the losses will be reduced as you will not have windings on rotor.But you have to go for intelligence in controlling the bldc motor i mean inverter based control.
Also some problems related to EMI/EMC may occur due to switching of the devices used for controlling the motor.

Otherwise ppl. have done work and replaced successfully IM with bldc motor.

I worked for Wellington Drives Technologies whose whole business approach is to replace existing (appliances) induction motors with SLOTLESS BLDC machines.
Depending what is a customer after, the replacement can result in radical efficiency increase, hence radical drop in power consumption. In these solutions, the machine itself costs about the same as the induction machine (BLDC machine is lots smaller, but contains NdFeB magnets, which aren't cheap), but the controller adds on additional cost...
If you have further, detailed questions, pls don't hesitate to mail me.
Best Regards,
Zvonko.