This is known from the Chinese TENAA certification page. On the page, there are three Xiaomi smartphones that appear with the code number M1804C3DE, M1804C3CCm and M1805C3CE. The first model comes with a dual camera maybe Redmi 6. While other models are foreseen as Redmi 6A. There is also a judge the three models Redmi 6 variants Pro and Plus.
Redmi 6 mentioned is equipped with 5.45 inch screen (720x1.440 pixels) and 18: 9 aspect ratio and comes with Android OS Oreo 8.1. This smartphone is also likely to come with an octa-core processor (estimated to be Snapdragon 625) speeds up to 2.0GHz. This page also mentions this device comes with 3000mAh battery.
All three models come with different RAM, camera, and storage options. For M1804C3DE, for example comes with 2GB / 3GB / 4GB RAM and 16GB / 32GB / 64GB storage space. This model has a 12MP main camera (unknown resolution from another camera) and 5MP front camera.