state the condition for max. current to be drawn from the cell

Dear student, 

In a circuit, the current flowing through the circuit is given as
$I=\frac{E}{R+r}$
where r is the internal resistance of the cell.
From the equation, it is evident that to draw maximum current from the cell, the external resistance of the circuit, R, should be zero.

Hope this clears your doubts.
Regards