What will be the value of resistor to be connected in series with freewheeling diode if brake coil is 110 V DC
The peak voltage across the resistor will be the coil operating current times the resistance. 

So if your coil is 100mA then 1K will allow the coil voltage to go from +110V to -100V. Your switching device will thus see 210V. 

The higher the resistance, the faster the field will collapse, but the higher the voltage the switching device will experience (if the resistor value is made really high, there may be a lot of ringing and/or the coil may break down from excessive voltage). 

So, pick an acceptable voltage, and calculate.