Enhanced compensation

If Property of X was taken over by CG,on 1/5/2015 he received 30lakhs as an intial compensation.

On 1/6/2016 court ordered 15 lakh as an enhanced compensation which was received on 1/9/2016.
He paid tax on enhanced compensation in AY 17-18.

On 1/5/2017 court ordered that,the enhanced compensation should be 12lakh only...

Then what will be the treatment of enhanced compensation already received and tax paid on it...???