Bluetooth Low energy chip range
Classic Bluetooth has 3 different classes which specify range.

Class     Maximum Power      Operating Range
Class 1   100mW (20dBm)   100 meters (330 Feet)
Class 2    2.5mW (4dBm)    10 meters (33 Feet)
Class 3      1mW (0dBm)     1 meter (3.3 Feet)


In practice, I have found most Class 2 Bluetooth devices  have a range of about 10 feet reliably.

Range is also affected by the usually things that effect a radio signal: Interference, antenna, walls, metal surfaces etc. 

In your case you are using BLE (Bluetooth Low Energy) which does not specify range like Classic Bluetooth. So range will depend on the reasons given above and also the module you are working with, and whether it has the capability to adjust power level.