50, 50, 50 and 50

Answer: 56

$\text{ 1 year = 12 months }\approx\text{ 52 weeks}$ and $1 \text{ month }\approx\text{ 30 days}$

$\begin{split}\text{Aroon's age}&=\text{50 years} + \underbrace{\text{50 months}}_{\text{4 years 2 months}} + \underbrace{\text{50 weeks}}_{\text{almost a year}} + \underbrace{\text{50 days}}_{\text{almost 2 months}}\\ &\approx \text{54 years + almost a year + 3 or 4 months}\\ &\approx \text{55 years and a bit} \end{split}$

So Aroon will be $56$ on his next birthday.