Pre deposit for filing an appeal in income tax

As per sec. 249 of IT act....

Sub sec.(4) reads as...

(4) No appeal under this Chapter shall be admitted unless at the time of filing of the appeal,—

(a) where a return has been filed by the assessee, the assessee has paid the tax due on the income returned by him; or

(b) where no return has been filed by the assessee, the assessee has paid an amount equal to the amount of advance tax which was payable by him:

Provided that, in a case falling under clause (b) and on an application made by the appellant in this behalf, the Commissioner (Appeals) may, for any good and sufficient reason to be recorded in writing, exempt him from the operation of the provisions of that clause.