In the circuit as shown in figure, the current in ammeter is:

The equivalent emf of the two cells in parallel circuit,

$\varepsilon_{eq}=\frac{\varepsilon_1 r_2+\varepsilon_2 r_1}{r_1+r_2}=\frac{3 \times 1+6 \times 2}{2+1}$ = 5V

The effective internal resistance of two cells in parallel circuit,

$r_{eq}=\frac{r_1 r_2}{r_1+r_2}=\frac{2 \times 1}{2+1}=\frac{2}{3}$Ω

The equivalent circuit will be as shown in figure.

Current in ammeter, I = $\frac{5 V}{10 \Omega+\frac{2}{3} \Omega}=\frac{15}{32}$ A