Tax paid by employee _form 16 filed &itr mandatory /not

A Bank employee who does not have any other source of Income Whose Gross Salary was Rs.7 lacs & Deductions were considered by employer.

Tax of Rs.25,000 paid & Tax payable is nil as per Form 16.

Is it mandatory for employee to file ITR in such cases where Tax payable as per Form 16 is NIL.

What are consequences of non filing of ITR in this case,if no tax is payable..