Having Some Issue with Marshmallow 6.0 in Walton Primo GH6+ smartphone

Hello Brother/Sister,
I am From Bangladesh. I am Using Walton Primo GH6+. its Specifications are:

-Android 6.0 Marshmallow
- 1.3 GHz Quad Core Processor
- RAM: 2 GB; ROM: 16 GB
​ - 5 inch HD Screen with Corning Gorilla Glass
- BSI 8 mega pixel Auto Focus rear camera with LED Flash
- BSI 5 mega pixel Front camera with Screen Flash
-Battery 2000mAh etc (for better view search this phone by name)

The Problems are two,
1) Battery Draining continuously no matter use it or not
2) Ram Problem. The OS Took 1.2GB so if I run any application its force stopped automatically.
Is there any Other Solution for this device. or Can You Suggest me any Good Rom for This Device to increase Ram availability?
If I Lollipop 5.1.1 Rom can suite this device I can also use that.

Thank You For Your Valuable time
Soummo
E-mail: soummo.billah@gmail.com

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