Hi, I'm Bhavik. Welcome to JustAnswer. I'm reviewing your question now, and will reply back ASAP.
All the keys are not working ? Do you see any light on your keyboard ?
Also check the battery of your keyboard. May be issue is in the battery of it.
There is no battery in a MacBook keyboard and the internal laptop battery should not be removed. Go to the Apple Logo to About this Mac then More Info or System Report select USB on the left then on the right do you see your internal keyboard listed? It will be named Apple Internal Keyboard / Trackpad:
Do you see Apple Internal Keyboard / Trackpad listed in System Report?
Do you still need help with this?