Income from house property

GD BHATIA (MBA) (4 Points)

21 September 2015  

Dear Sir,
I had three house property in different cities as given below:
1. Flat at Delhi purchased thru house loan in 2003 -HBA interest @ 10.1 % floating, Interest approx 25000 for FY 2015-16
(Till now I m showing it self occupied )
2. Flat at Alibag ( Place of posting and I m living at present in this house )purchased thru house loan in 2011 - loan repaid fully.
( Till now I m showing this as let out -since my company is paying BAER after  deducting tax @ 30 % approx to me and I m living in this property .)
3. A house build by self at kanpur ( No loan -My parents are presently living there .)
I m not showing this property in ITR for AY 2015-16.
As my wards are living at Navi mumbai for education in a rented accommodation ,I m getting HRA for Mumbai and BAER {Bachelor accommodation expense reimbursement (fully taxable) } at alibag for myself. I am a psu employee and my gross income is approx 20 Lacs.
Now please guide me 
1.Is it mandatory to show all residential properties in ITR ?
2. How to calculate Income from house property now for FY 2015-16 ?
Regards ,

Gulshan