Devices including Latest MT67XX Devices MT6735, MT6737, MT6752. Step by Step guide to backup NVRAM aka IMEI bluetooth and mac address. Go to the Get Version tab and select IMEI Download. MTK 65xx DEVICES IMEI REPAIR TOOLS,Xiaomi MIUI Official Forum.
How to Restore NVRAM.bin Using SP Flash Tool. If you don't have nvram.bin backup then download.