Hi
You have to file your ITR on or before due date (generally 31st July) for c/f loss which can be adjust in future year income, but as you dont file the same on time thus loss cant be c/f but you can still file your ITR of AY 2016-17 & 2017-18 by March 2018.
For AY 2016-17 choose ITR FORM 4
For AY 2017-18 choose ITR FORM 3