If you are using any RDA chpset based android phone and want to repair IMEI in RDA chipset based devices then download RDA IMEI Tool from the below link and write new IMEI number on any RDA chipset based android phone.RDA IMEI flashing tool allows you to write imei number on your android device with in a single step.
Here is full detail tutorial to learn “how to repair IMEI in RDA chipset and how to use RDA IMEI tool to flash IMEI number”