I had filed my returns with incomplete details . Can I re-file with correct details ?

I had taken a loan in 2013 for Rs 22 Lakhs   and had paid around Rs 2 Lakhs as interest and Rs 12K as Principal in 2014 . The house was under construction  , Although the house was handed over to me in Feb 2014 . But I started occupying it only from June 2014.

I had claimed HRA as per my existing for the entire tax AY 2014-15 since I was staying in a rented home . I was under the assumption that I can claim House Loan for tax deduction only after occupying the house. Recently I came to know that it is not the case  and I have some benefits in declaring house loan for houses under construction.

Please let me know if it  is possible for me to refile tax returns. Also what benefits I would get in my case. Also let me know if you need exact amount detials of loan etc.