Given that, principal, $P=₹15000$ and time period, $n=2$ years . 
Let the rate of interest per annum be $r$. 
Simple interest in 2 years 
$S.I=\frac{15000\times r\times 2}{100}$
$\Rightarrow S.I=300r$
Compound interest $C.I=A-P=15000(1+\frac{r}{100}{)}^2-15000$, here, $A$ is the amount.
Given that $C.I-S.I=96$   
(Since C.I > S.I)
$\Rightarrow 15000(1+\frac{r}{100}{)}^2-15000-300r=96$
$\Rightarrow 15000(1+\frac{r}{100}{)}^2-300r=15096$
$\Rightarrow 15000(1+\frac{r^2}{10000}+\frac{2r}{100})-300r=15096$
$\Rightarrow 15000+\frac{15r^2}{10}+300r-300r=15096$
$\Rightarrow \frac{15r^2}{10}=96$
$\Rightarrow 15r^2=960$
$\Rightarrow r^2=64$
$\Rightarrow r=\pm 8$
$\because$ Rate of interest cannot be negative, so $r=8\%$