Nexus 9 is manufactured by HTC. It features an 8.9″ IPS LCD display with 1536 x 2048 resolution. It’s powered by an Nvidia Tegra K1 dual-core 2.3GHz processor and 2GB of RAM. Internal storage is available in either 16GB or 32GB. The Nexus 9 features a large 6700mAh battery, and 8MP camera, with 1080p video recording, along with a 2.1MP secondary front facing camera.
Paranoid Android team have rolled their 5.1 ROMs for Nexus series. It can be installed on Nexus 9. It is quite a stable version and has very less bugs. If you want to install Paranoid Android 5.1 on Nexus 9, follow the guide below.