install adb and fastboot (minimal adb & fastboot for windows and via pkg manager in linux) 1.Download deeptest for realme c11 as all tools/roms of c11/c12 and c15 are same https://drive.google.com/file/d/1S2PgEJ84ckCD4dYpmNjwBZt2qoZolWZ8/view?usp=sharing 2. start applying and after 1bout 15 minutes you will get review successful. 3.start in depth test and device will start in fastboot mode 4. fastboot flashing unlock [may need sudo] 5. select unlock bootloader [this step will wipe user data so backup if necessary] 6.to install magisk download magisk apk , stock boot.img of c15 rom and vmbeta.img to bypass boot verification( Optional ? not sure) vmbeta.img: https://drive.google.com/file/d/1W-14CBShXQoIZonuRGo_sliO3anWw2Jj/view?usp=sharing stock boot.img https://drive.google.com/file/d/1QUsmkzrs_q8oGJLeWOHhqDNOTSobUd_O/view?usp=sharing 7.patch boot.img to get magisk_patched_something.img file move files , vmbeta.img and magisk_patched_something.img to adb directory or start