Huawei never released an official Android 6.0 Marshmallow update for the MediaPad T1 7.0 (model numbers: T1-701u, T1-701w, T1-701f, or T1-A21W). When the device was in its prime, Huawei’s update policy for budget tablets was limited to 18 months of support. The T1 7.0’s hardware—powered by the Spreadtrum SC7731G or Qualcomm Snapdragon 200 (depending on variant)—was considered too low-end by Huawei’s engineers to handle the memory management and permissions overhaul of Marshmallow efficiently.
Searching for "Huawei MediaPad T1 7.0 Android 6 Update" will lead you to shady websites offering Update.zip files. Here is what they actually contain: Huawei Mediapad T1 7.0 Android 6 Update
Android 6 is heavier than KitKat. If the tablet feels sluggish, disable animations in the Developer Options. Should You Update? Huawei never released an official Android 6
Marshmallow allowed formatting SD cards as internal storage. On Lollipop, use (requires root). Steps: Searching for "Huawei MediaPad T1 7
Before you give up on the Huawei MediaPad T1 7.0 Android 6 dream, here is your practical action plan: