Itr return not filed, notice received

Gargi (CMA) (31 Points)

07 September 2015  
Due to some unavoidable circumstances I could not file my itr return for f.y 2012-13 and now I Hv received a notice to furnish my response under compliance module for non filing of return. Is there any way that I can file the return now? Also please tell me how to furnish the compliance.