Rental income from commercial property

My dad has leased out commercial property @ Rs 30000/- per month.
Rent is recerived after TDS deduction @ 10%  = Rs 27000/- per month.
What would be the taxable income and net tax payable of my father with regard to this rent received?
Please help and elaborate with calculations if possible. Also provide any ways of tax planning/saving regarding the same. Thanks.