Income tax on sale of asset

sujin (accounts executive) (222 Points)

14 June 2023  
Dear expert,
my aunty having flats in apartment she has no heir she was passed away last year .we are nominal for all her asset we are planning to sell that apartment now the buyer telling to pay 50percent through online 50 percent by cash
now my query is whether we need to pay tax for that cash amount?
please try to send any link too for above case relative