Tax on housing loan

Hi

 I would like to know what types of tax exemption on home loan are possible in my case, and good timing for my possession.

I purchased property in Aug 13 and started Home loan EMI in Nov 14. So far I haven't taken any kind of exemption whatsoever against my home loan. What are all possible rebates I can get on i) Principal repaid and ii) Interest paid?
Builder plans to grant me possession in Mar 17. But that won't leave me any time for claiming any exemption. Should I be better off deferring the possession to next FY (17-18).

Thanks so much!