Here is a stock ROM, MTK Backup for Opsson 6611.
With this Opsson 6611 flash file, you can flash stock ROM back to your Opsson 6611 using SP Flash Tool. This is mostly required when you have software issues with your Opsson MTK Android devices, need to revert your Opsson 6611 to factory state or unroot by flash.
Meanwhile, in most cases, flashing stock ROM on Opsson android devices corrects all software errors if you know how to do it.
Below here is the download link for the stock ROM. You may also see the tutorial page on how to flash stock ROM on Opsson and other MTK android devices below.
Opsson 6611 Stock ROM Download Link
Download Opsson 6611 Stock ROM Here
Helpful Links
How to Flash Stock ROM On Opsson IVO 6611