Capital gain on compulsory acquisition of capital asset

if government acquired a land (other than agricultural land and ancestral property acquired prior to 2001) under compulsory acquisition on 2012 and instead of amount, given developed site as compensation in the fy 2019-20.
1) can compulsory acquisition treated as sale of property?

2) which one to consider for cost of acquisition whether it's NIL or market value of 2001 (if we don't know the value of acquisition value) for calculation of capital gain