Intimation 143(1)a wrong head

GST CENTRE (92 Points)

06 February 2020  
dear experts,
one of our client had is received rental income of Rs. 28L. for which Tds is deducted for AY 17-18.
while filing return u/s139(4) he declared the rental income as under the head of "income from other sources" for Rs. 12L. department issued assessment order in 19/3/2019 including the income of " RENTAL INCOME" Rs. 19+L.
client ignored the intimation order.

now department issued demand of Rs. 7.39L.
ITO had informed client to pay 20% of demand and go for appeal.

my query is...

any possibilities of going for appeal?
if possible, please mention under which section?

thank you in advance..