Complaince letter received from income tax for f.y. 2012-13

Respected Sir,

I came across a case where the client has received compliance letter from IT departmetn for non filling of return for F.Y. 2012-13, as there are certain transactions which indicates that the income was taxable for that particular period.

Since the time limit has already lapsed to file return for this period, what should be the course of action. Could you please advice.

Thanks

CA ANAND