Only 512 Mb of RAM, that sucks!
The general apps we use like facebook, messenger, WhatsApp won't run smoothly on it. You'll face lags I guarantee.
A phone should contain minimum 1Gb of RAM, to me. This is the basic feature a phone should have. Ram is he most important feature of all, Eveytime I go out to buy a new phone, I always check the Ram first. Lenovo A616 also have 0.3 MP camera, that'ts awful to.
I would suggest you to get A916, which has atleast 1 GB RAM and 5MP front came, which is better. You can see the comparison here if you want:
http://www.china-prices.com/phone-versus/517-1092/lenovo-a916-vs-lenovo-a616
Though there are a lot of better phones out there,And I never used a Lenovo
xD