micromax q338 mtk 6580 version 5.1-how rebuild imei?

this version 5.1 can not rebuild imei in advance box,miracle box.

i have done many imei by sigma key.but it need root first.

this version 5.1 root not sucess in king root and i root.

any friends have 4.1.2 version for q338?

this version support for root-so can rebuild imei easily.

help me