Link Upd - Oppo A11k Custom Rom
The Oppo A11k (CPH2082) uses the MediaTek Helio P35 chipset and shares much of its hardware with the Oppo A12. Because of this, custom ROMs developed for the A12 are often compatible with the A11k, though you should always verify the specific build notes for your exact model.
Corvus ROM: Often chosen by users looking for a "gaming-centric" build with performance tweaks. Essential Download Links & Resources oppo a11k custom rom link
Transfer the ROM: Move the file to your phone's internal storage or an SD card. Boot to Recovery: Power off, then hold Power + Volume Down. The Oppo A11k (CPH2082) uses the MediaTek Helio
Install ROM: Go to Install, locate your ROM file, and swipe to confirm. locate your ROM file

