Please note that the relationship, between the temperature in Kelvin degrees and Rankine degrees is:

°Rank * (5/9) = °K

so you can compute the Kelvin tem,perature starting from your Celsisus temperature and then applying te formula above you can get your temperature measured using the requested unit of measure namely Rankine.

Example if your temperature is 25 Celsisus degrees, then your temperature measured with Kelvin degrees is:

25 + 273.15 = 298.15 Kelvin degrees, then I apply that formula above, namely I multiply by 5/9 and I get:

298.15 * 5/9 = 165. 64 Rankine degrees,

So we can say that:

25 Celsius degrees are equivalent to 165.64 Rankine degrees