Income tax

You can file return for 2 years easily. If your income was taxable then you are mandatorily required to file the return. However, if inome is not taxable and you want to file the return voluntarily you can also do that but with some penalty as per below details - 

For FY 2014 - 15, you can file return in FY 16 - 17, but you will be liable for penalty of Rs. 5,000 along with interest on tax if any.

For FY 2015 - 16, you can file return in FY 16 - 17.

Returns can be filed online by chossing the ITR form based on nature of income.

More details will depend on the facts of your case.

Thanks.

You can file 2 returns as per sandeep advice

you can file the FY 2013-14 return as manual return with AO