There is a CM11 ROM for the Samsung Galaxy Core Duos so why not a MIUI ROM? The ROM is based on KitKat ROM. Here are the features of this ROM:
1. Deodexed
2. Highly modified
3. All build Prop tweaks
4. Fully themed
5. Smooth performance
6.Miui Launcher
7. Miui File explorer
8. Miui Music player
9. Miui Gallery
10. Miui Camera
11. Miui lockscreen
12. Themed statusbar
13. Themed every app
14. Fully tweaked
15. Theme changer
For installation follow these steps:
Download the ROM from here
Root Samsung galaxy core by following these instructions
Install cwm recovery from here
Boot to cwm by pressing home+power+volume up simultaneously
Clear data . cache
Install Miui style v5