Here is an Android 4.2.2 Jelly Bean rooted firmware for the PIPO M6 (3G model) tablet based on latest official update from Pipo dated 2013/06/25

(M6_3G_update_20130625.img)

Kernel: Linux version 3.0.36+ (hkw@mid-server) (gcc version 4.4.3 (GCC) ) #17 SMP PREEMPT Tue Jun 25 16:06:31 CST 2013

Android 4.2.2 JB: rk30sdk/rk30sdk/rk30sdk:4.2.2/JDQ39/eng.ljh.20130625.200611:eng/opinions-on-teclast-p90hdst-keys

Custom firmware features:

• root with latest SuperSU version 1.41 (free version)
• removed most Chinese and unnecessary applications, removed Certificate Center asking for product key
• Google Play Store fixes so more application are visible/compatible
• updated busybox v1.21.0.git (2012-11-29)
• Unix like init.d boot scripts support, more details on init.d scripts here
• changed permissions on external sdcard to allow write access
• increased space for applications (/data partition) to 4 GB

Download: kasty-pipo-m6_3G-422-20130625-rooted4.zip

Flash with Rockchip Batch Tool version 1.7, use Restore button.

Please report any problem with this firmware, I can't verify this custom firmware works as I don't have a PIPO M6 tablet to test the custom firmware.