Install Android 6.0 Marshmallow On your phone by following the below link.
CyanogenMod is a custom ROM built by the community of developer. it is a free and open source software based on the official releases of Android by Google, with added original and third-party code. It is based on a rolling-release development model. CM13 has a lot of features such as Cyanogenmod Launcher, Themes, Notifications, Lock screen, Buttons, System Profiles, Status Bar, Privacy, etc.
Android 6.0–6.0.1 “Marshmallow” (codenamed Android M during development) is the 6th major version of the Android operating system. First unveiled in May 2015 at Google I/O, it was officially released in October 2015.
Marshmallow primarily focuses on improving the overall user experience of its predecessor, Lollipop. It introduced a new permissions architecture, new APIs for contextual assistants (first used by a new feature “Now on Tap” to provide context-sensitive search results), a new power management system that reduces background activity when a device is not being physically handled, native support for fingerprint recognition and USB Type-C connectors, the ability to migrate data and applications to a microSD card, and other internal changes.
When your device is at rest, Doze automatically puts it into a sleep state. So your phone can still set off your alarm in the morning even if you forgot to charge it. Phew!
No more battery drain from seldom used apps: App Standby limits their impact on battery life so your charge lasts longer.
Permissions your way
No need to give apps access all the time. Android Marshmallow lets you define what you want to share and when. Turn permissions off at any time, too.
Simplified security with your fingerprint
Skip the crazy passwords: The key is at hand. Your fingerprint unlocks your phone and lets you securely breeze through sign in, the Play Store and even in apps.