Dear Sir,
You should immediately file ITR of two years 2014-15 and 2015-16.
As per section 271F If a person who is required to furnish a return of his income, as required under sub-section (1) of section 139 or by the provisos to that sub-section, fails to furnish such return before the end of the relevant assessment year, the Assessing Officer MAY direct that such person shall pay, by way of penalty, a sum of five thousand rupees. which is generally not levied.
For any further clarification feel free to contact us.