Moto G4 Plus and One plus 2 are not from the same price segment. Moto G4 Plus costs around 14k–15k INR and One Plus 2 comes around 19k-20k INR.
So, if you are giving more money for a One Plus 2 then you can expect many more features from one plus 2.
Moto G4 plus has Qualcomm Snapdragon 617 processor, 3 GB RAM, 32 GB Storage, 3000 mAH battery, voLTE support and 16 MP camera.
One plus 2 have Qualcomm Snapdragon 810 processor, 4 GB RAM, 64 GB Storage, 3200 mAH battery, 13 MP camera.
One plus 2 was launched in July 2015 where Moto G4 Plus was launched recently (May-June 2016).
Final Conclusion: From the both phones, prefer Moto G4 plus as it provides expandable storage up to 128GB, better camera and voLTE support and lower cost.
And if you are One Plus fan, buy One plus 3. It will cost you more but, It is a High end device with many new features and excellent community support.