How is Zakat on money valued in Qatari Riyals to be paid by a person residing in Qatar, and is it permissible to pay it in Qatar, or must it be paid in Tunisia, and how is the value of Zakat converted into Tunisian Dinars given the fluctuating exchange rate?

Zakat (definition) becomes obligatory on your wealth if it reaches the nisab (definition) and one hawl (lunar year) has passed over it. The nisab for currency is equivalent to 85 grams of gold or 595 grams of silver. Zakat is to be paid at a rate of 2.5% of the wealth, and the general rule is that zakat should be disbursed in the country where the wealth is located.